Let me start with a confession: I didn’t grow up eating Tennessee Onions. Actually, I stumbled onto this recipe by accident after a potluck where someone brought a bubbling, golden casserole that had everyone fighting for seconds. I managed to snag the last scoop (and yes, I scraped the pan), and then spent the next week chasing down the cook for her secret. Turns out, it was this easy, cheesy Tennessee Onions recipe—simple, comforting, and honestly, a little addictive.
This dish is the kind of side that doesn’t try to be fancy. It’s just good. Melted cheese. Sweet onions. A little butter. I’ve made it for holiday dinners, backyard barbecues, and even as a midnight snack (no shame). The best part? It’s basically impossible to mess up. And if you love recipes that make your kitchen smell like pure comfort, this one’s about to become your new favorite.
So anyway, if you’re looking for a crowd-pleasing side dish that’s easy enough for a weeknight and delicious enough for a Sunday supper, this Tennessee Onions recipe is it. Grab your casserole dish—let’s get into the cheesy goodness.
Why You’ll Love This Tennessee Onions Recipe
Okay, real talk—this recipe has ruined plain onions for me. There are so many reasons I keep coming back to it, and here’s the rundown:
- Ridiculously Easy: Slice, layer, sprinkle, bake. That’s it. I’ve made this with a toddler clinging to my leg and it still turned out perfect.
- Cheese Pulls for Days: The combo of cheddar and mozzarella gives you that epic stretch. If you’re about the cheese, this is your side dish soulmate.
- Sweet, Soft Onions: Baking transforms them into something almost luxurious. Even people who “don’t like onions” have asked for seconds.
- Budget-Friendly: Onions, cheese, butter—nothing fancy, nothing expensive. I usually have everything on hand, which is dangerous because I make it way too often.
- Works for Any Meal: I’ve served this next to steak, grilled chicken, burgers, and even breakfast eggs. No one complains.
- Make-Ahead Magic: You can prep it early and bake when you’re ready. I do this for big family dinners so I’m not stressed at the last minute.
This Tennessee Onions recipe is pure comfort food—the kind that makes people close their eyes while they eat. I love it for lazy weekends, potlucks, and honestly, any time I want to feel like a kitchen hero without breaking a sweat.
What Ingredients You’ll Need (Plus My Must-Know Tips)
Here’s why I’m obsessed with this ingredient list: it’s short, forgiving, and you probably have most of it in your fridge already. I’m picky about a couple things, though, so I’ll share my favorites and some swaps.
- Sweet Onions (3-4 large, about 2 lbs / 900g): Vidalia is the classic, but I’ve used Walla Walla and regular yellow onions too. The sweeter, the better. Slice them into thick rounds—about 1/2 inch (1.25 cm).
- Cheddar Cheese (2 cups / 225g, shredded): Sharp cheddar gives the best flavor punch. I always shred my own—pre-shredded is fine in a pinch, but doesn’t melt as nicely.
- Mozzarella Cheese (1 cup / 115g, shredded): Adds that gooey factor. You can swap in Monterey Jack or even provolone if you want something different.
- Parmesan Cheese (1/2 cup / 50g, grated): Adds a salty kick and helps brown the top. I use the real stuff, not the green can, but do what you gotta do.
- Butter (1/2 cup / 115g, melted): Salted or unsalted both work. I usually go salted because it’s what I have.
- Garlic Powder (1 tsp): Not strictly traditional, but I add it for a little extra oomph. Feel free to leave it out or use fresh garlic.
- Salt & Pepper (to taste): Start with 1/2 tsp salt and 1/4 tsp pepper, then adjust if you want more.
Quick note: If you want to go wild, you can add a sprinkle of paprika or cayenne on top for color and a tiny bit of heat. And if you only have regular onions? Slice them and let them soak in cold water for 10 minutes—mellows the bite.
Substitutions I’ve tested:
- No cheddar? Use Colby or even Swiss.
- Lactose-free? Violife cheddar shreds work surprisingly well.
- Low-fat? You can use reduced-fat cheese and less butter, but, uh, it won’t be as decadent.
I learned the hard way that onions sliced too thin will disappear into mush. Keep them chunky for that perfect melt-in-your-mouth-but-still-there texture.
Equipment Needed (No Fancy Stuff Required)
You don’t need a chef’s kitchen for Tennessee Onions—just the basics.
- 2-qt (2 liter) Casserole Dish: I use my ancient Pyrex, but any oven-safe dish works. If you double the recipe, use a 9×13-inch (23×33 cm) pan.
- Chef’s Knife: For slicing onions. I love my slightly dull knife because I’m less likely to cry.
- Cutting Board: Bigger is better. Those onion rounds can be slippery.
- Mixing Bowl: For tossing onions with seasoning and butter (I skip this and mix right in the dish sometimes).
- Measuring Cups & Spoons: I eyeball the cheese, but if you want perfect layers, measure it out.
- Aluminum Foil: For covering the dish if you want a softer, less browned top.
If you don’t have a casserole dish, a deep pie plate or even a Dutch oven will work. Just make sure it’s oven-safe. And if you’re feeling extra, a mandoline will give you perfect onion slices (watch your fingers—I’m speaking from experience).
Personal note: My favorite kitchen “tool” is actually a wide spatula for scooping out big, cheesy servings. The messier, the better.
How to Make Tennessee Onions: Step-by-Step
Alright, let’s do this! I’m walking you through exactly how I make Tennessee Onions, with all my little tricks along the way.
- Preheat & Prep (5 minutes)
Preheat your oven to 350°F (175°C). Grease your casserole dish with a swipe of butter or cooking spray. - Slice the Onions (5 minutes)
Peel and slice 3-4 large sweet onions into thick rounds (about 1/2 inch / 1.25 cm). Separate the rings and layer them evenly in the dish. Each layer should look kind of like a messy lasagna—don’t stress about perfect stacking. - Season & Butter (3 minutes)
Sprinkle onions with salt, pepper, and garlic powder. Pour melted butter over the top, making sure it gets into all the nooks and crannies. I jiggle the dish to help it settle. - Add Cheese Layers (3 minutes)
Sprinkle cheddar cheese over the onions. Add mozzarella next, then finish with Parmesan. You want a generous blanket of cheese—don’t skimp! - Bake (35-40 minutes)
Slide the dish into the oven, uncovered. Bake until the top is golden and bubbly, and the onions are tender when you poke them with a fork. You’ll smell buttery, cheesy magic about halfway through. If the top is browning too fast, cover loosely with foil for the last 10 minutes. - Rest & Serve (5 minutes)
Let the casserole sit for about 5 minutes before scooping. The cheese will set up a bit, and it’ll be easier to serve.
How do you know it’s done? The sides will be bubbling, the top will be golden brown, and a fork should slide into the onions with no resistance. If you’re a cheese fiend, broil the top for 2 minutes at the end for max crunch.
Troubleshooting: If you see a lot of liquid, it’s normal—sweet onions release juice. Just spoon carefully and let it rest a bit longer. If you want firmer onions, bake 5-10 minutes more.
At this point, you’re about 50 minutes in and ready for the best cheesy side dish ever. Tennessee Onions for the win!
My Best Tips & Techniques for Perfect Tennessee Onions
Okay, here’s where I spill all my secrets from making this recipe way too many times.
- Don’t skimp on onion thickness: Thick slices (1/2 inch / 1.25 cm) hold up and get meltingly soft—not mushy.
- Shred your own cheese: Pre-shredded is fine, but freshly shredded cheese melts smoother and tastes richer.
- Use sweet onions: Vidalia, Walla Walla, or even Maui. Regular yellow onions work, but you’ll need to soak them in cold water for 10 minutes to mellow the flavor.
- Rest before serving: Let the casserole sit for 5-10 minutes. It helps the cheese firm up and makes serving way easier.
- Broil for crunch: Broil the top for 2 minutes if you love crispy cheese edges (highly recommend).
- Make ahead: You can prep everything in the dish, cover, and refrigerate up to a day ahead. Bake straight from the fridge, adding 5 extra minutes to the cook time.
- Double for a crowd: This recipe scales easily. Just use a bigger dish and add a few minutes to baking time.
Quick tip: If you want a deeper flavor, sprinkle a little smoked paprika on top before baking. My husband swears by it.
And don’t worry if your onions look messy—this is rustic comfort food. Imperfection is part of the charm.
Ways to Mix Up Your Tennessee Onions Recipe
Once you’ve made the classic version, you can get creative. I’ve tried all of these, and they all totally work.
- Bacon Lovers: Add 1/2 cup (75g) cooked, crumbled bacon on top of the cheese before baking. Smoky, salty, next-level.
- Spicy Kick: Sprinkle 1/2 tsp crushed red pepper flakes or a dash of hot sauce over the onions.
- Herb Upgrade: Use fresh thyme or rosemary (1 tbsp, chopped) between onion layers. Adds a fancy touch.
- Low-Carb Version: Cut the butter in half and use only mozzarella and Parmesan. Still cheesy, less rich.
- Loaded “Casserole”: Mix in 1 cup (150g) cooked, chopped potatoes or even cooked rice for a heartier dish.
- Gluten-Free: Good news—this recipe is already gluten-free! Just double-check your cheese if you’re sensitive.
- Dairy-Free: Use vegan butter and non-dairy cheese shreds. I’ve done this for friends with allergies—Violife cheddar and mozzarella are solid options.
- Extra Veggies: Add sliced bell peppers or mushrooms to the onion layers. My kids like the color (and it sneaks in veggies).
If you want to get really wild, try adding a layer of crushed Ritz crackers or crispy fried onions on top. It’s not traditional, but it’s delicious.
Personal favorite: Bacon and thyme. I make this version for special occasions, and there are never leftovers.
Serving Ideas & Storage
How to Serve Tennessee Onions
- Classic Side: Scoop generous servings next to grilled steak, pork chops, or roasted chicken.
- Breakfast Vibe: Top with a fried egg and serve with toast. It’s surprisingly good for brunch.
- Potluck Hero: Bring it in a disposable pan for easy cleanup. People will ask for the recipe, promise.
- Snack Attack: Pile onto crusty bread or crackers for a melty-cheesy snack.
- Fancy Brunch: Serve with fresh herbs and crumbled feta for a Mediterranean twist.
For presentation, I like to sprinkle a little extra Parmesan or fresh parsley on top right before serving. Makes it look fancy with zero extra effort.
Storage Tips
- Room Temp: Cool leftovers and store in an airtight container up to 2 days. It’s even better the next day!
- Refrigerator: Lasts 4-5 days. I reheat single servings in the microwave for 30 seconds.
- Freezer: Yes, you can freeze it! Freeze in portions, wrapped well. Thaw overnight and reheat at 325°F (160°C) for 15 minutes.
- Reheating: Oven is best for crispy top (350°F / 175°C, 10 minutes), but microwave works for speed.
Pro tip: If it gets a little dry, add a splash of cream or milk before reheating. Or, if you’re feeling wild, use leftovers in grilled cheese sandwiches. So good.
Nutritional Info & Health Benefits
I’m not a nutritionist, but here’s why I feel okay about eating this cheesy Tennessee Onions recipe more often than I’d probably admit.
| Per Serving (1/8 casserole) | Amount |
|---|---|
| Calories | ~210 |
| Protein | 7g |
| Carbs | 14g |
| Fat | 13g |
| Fiber | 2g |
- Onions are high in Vitamin C and fiber—so hey, you’re getting veggies!
- Cheese adds calcium and protein, making this a little more filling than your average side dish.
- Low sugar, and if you skip the extra butter, it’s lighter than most casseroles.
I love that this fits into my weeknight dinners without feeling like a splurge. Sure, it’s comfort food, and yes, there’s cheese and butter—but compared to creamy potato casseroles, Tennessee Onions are practically health food (okay, maybe not quite, but close!).
Final Thoughts
So that’s my Tennessee Onions recipe—honestly one of the best easy cheesy side dishes I’ve ever made. I know I’ve gone on about it, but when you find a recipe this comforting, you just want to share it with everyone.
This is my go-to for family dinners, potlucks, and those nights when I want something warm and simple that everyone loves. I hope it becomes your favorite too.
Make it your own! Try the bacon, add the herbs, swap the cheese, get creative. That’s how the best recipes happen. And if you make this, I’d LOVE to hear how it turns out. Drop a comment below, tag me on Instagram @yourhandle (I seriously get excited seeing your cheesy creations), or ask me anything in the comments—I check them every day.
Happy baking! Hope your kitchen smells as amazing as mine does right now.
FAQs: Tennessee Onions Recipe
Q: Can I use regular yellow onions instead of sweet onions?
A: Yep! I’ve done this a bunch. Just soak the slices in cold water for 10 minutes before layering—they’ll taste milder and less sharp. Sweet onions are best, but regular works in a pinch.
Q: Can I make Tennessee Onions ahead of time?
A: Absolutely. Assemble everything, cover tightly, and refrigerate up to 24 hours before baking. Add 5-10 minutes to baking time if it’s cold from the fridge.
Q: What cheeses work besides cheddar and mozzarella?
A: I’ve tried Monterey Jack, Colby, Swiss—even Pepper Jack for a spicy kick. As long as it melts well, you’re good. Mix and match based on what’s in your fridge.
Q: Is this Tennessee Onions recipe gluten-free?
A: Yes! No flour or breadcrumbs needed. Just double-check your cheese if you’re super sensitive—sometimes pre-shredded brands add starch.
Q: Can I double the recipe for a big crowd?
A: For sure. Use a 9×13-inch (23×33 cm) pan and double everything. Bake about 5-10 minutes longer. I do this for parties and it never lasts long.
Pin This Recipe!
Tennessee Onions Recipe: Easy Cheesy Side Dish Everyone Loves
- Total Time: 55 minutes
- Yield: 8 servings 1x
Description
This Tennessee Onions recipe is a simple, comforting casserole featuring sweet onions baked with layers of gooey cheese and butter. It’s an easy, crowd-pleasing side dish perfect for holidays, potlucks, or weeknight dinners.
Ingredients
- 3–4 large sweet onions (about 2 lbs), sliced into 1/2-inch thick rounds
- 2 cups (8 oz) sharp cheddar cheese, shredded
- 1 cup (4 oz) mozzarella cheese, shredded
- 1/2 cup (2 oz) Parmesan cheese, grated
- 1/2 cup (1 stick) butter, melted
- 1 teaspoon garlic powder
- 1/2 teaspoon salt (or to taste)
- 1/4 teaspoon black pepper (or to taste
Instructions
- Preheat your oven to 350°F (175°C). Grease a 2-quart casserole dish with butter or cooking spray.
- Peel and slice the onions into thick 1/2-inch rounds. Separate the rings and layer them evenly in the casserole dish.
- Sprinkle the onions with salt, pepper, and garlic powder. Pour the melted butter evenly over the onions, making sure it gets into all the layers.
- Sprinkle the cheddar cheese over the onions, followed by the mozzarella, then the Parmesan, creating a generous cheese layer.
- Bake uncovered for 35-40 minutes, until the top is golden and bubbly and the onions are tender when pierced with a fork. If the top browns too quickly, cover loosely with foil for the last 10 minutes.
- Let the casserole rest for 5 minutes before serving to allow the cheese to set.
Notes
For best results, use sweet onions like Vidalia or Walla Walla. Shred your own cheese for optimal melting. Let the casserole rest before serving for easier scooping. For a crispy top, broil for 2 minutes at the end. You can prep the dish ahead and refrigerate before baking. Add bacon, herbs, or extra veggies for variations. This recipe is naturally gluten-free—just check your cheese labels if sensitive.
- Prep Time: 15 minutes
- Cook Time: 40 minutes
- Category: Side Dish
- Cuisine: Southern
Nutrition
- Serving Size: 1/8 of casserole
- Calories: 210
- Sugar: 5
- Sodium: 350
- Fat: 13
- Saturated Fat: 8
- Carbohydrates: 14
- Fiber: 2
- Protein: 7
Keywords: Tennessee onions, cheesy onions, onion casserole, Southern side dish, easy casserole, gluten-free side, comfort food, potluck recipe, Vidalia onions, baked onions
