Tennessee Onions Recipe

Tennessee Onions are the kind of recipe that makes you look like a kitchen genius without breaking a sweat. These thick slices of sweet onions get smothered in butter and cheese, then baked until they’re bubbling and golden on top.

I remember Betty making these one Sunday when we were expecting company and she realized she’d forgotten to pick up anything for a side dish. She grabbed three big Vidalia onions from the pantry, pulled out whatever cheese was in the fridge, and threw this together in about 15 minutes. When she pulled that dish out of the oven with the cheese all golden and bubbly, you’d have thought she’d been planning it for days. The onions had gone sweet and tender, and that crispy cheese on top had everyone scraping the pan for every last bit. One of the neighbors asked for the recipe, and Betty just laughed and said, “Honey, it’s so easy it feels like cheating.” Time to get our hands floury!

What Makes This Cheesy Onion Bake So Special

Betty always believed the best recipes are ones you can throw together on a Tuesday night but still feel proud to serve on Sunday. Tennessee Onions fit that bill perfectly. This recipe came from a neighbor years ago, and Betty tested it dozens of times until she got the cheese blend and timing just right.

Here’s why this recipe belongs in your rotation:

• Ready in just 50 minutes with only 15 minutes of hands-on work while the oven does the heavy lifting.
• Uses ingredients you probably have sitting in your fridge right now – onions, butter, and whatever cheese needs using up.
• Forgiving enough that you can swap cheeses, adjust seasonings, or even make it a day ahead without any trouble.
• Creates that irresistible golden, bubbly cheese top that everyone fights over at the table.
• Actually tastes better the next day after the flavors have had time to meld together overnight.
• Works beautifully alongside grilled meats, roasted chicken, or even piled on toast for breakfast.

Key Players in This Recipe

Sweet onions (Vidalia preferred): These become incredibly tender and almost caramelized as they bake, losing any sharpness and developing a mellow sweetness that balances the rich cheese. I always choose Vidalia when they’re available at the market, but large yellow onions work just fine when sweet onions aren’t in season.

Unsalted butter: This melted butter coats every onion ring and helps the seasonings stick while adding richness throughout the dish. Betty melts it completely before drizzling so it finds its way into all the nooks and crannies between the onion layers.

Cheddar cheese: Sharp or medium cheddar brings bold flavor and creates those coveted crispy, golden bits on top that Betty always called “the treasure.” In my kitchen, I prefer a good quality block cheese that I shred myself for the best melting.

Monterey Jack cheese: This mild, creamy cheese ensures everything melts together smoothly without becoming greasy or separated. Jack is the glue that holds the cheese layer together while adding a nice stretch.

Parmesan cheese: Freshly grated Parmesan adds a salty, nutty depth and helps create that golden crust on top. I’ve found that the real stuff grates finer and browns more evenly than the pre-shredded kind.

Garlic powder: A full teaspoon brings savory depth without the risk of burning that fresh garlic would have under the broiler. It distributes evenly across every layer, giving consistent flavor in every bite.

Dried thyme: This subtle herb Betty discovered adds an earthy note that makes the dish feel more sophisticated than its simple ingredient list suggests.

Salt and black pepper: These basic seasonings enhance everything else, though Betty always went easy on the salt since the cheeses bring plenty of their own.

How to Make Tennessee Onions

Step 1. Preheat your oven to 375°F and give a 9×13-inch baking dish a light coating of cooking spray or butter. I’ve learned that this quick step saves you from scrubbing stuck-on cheese later.

Step 2. Peel your sweet onions and slice them into half-inch rings, then spread them in an even layer in your prepared dish, gently separating the rings as you arrange them. Betty’s tip: Keep those slices consistent – too thick and they stay crunchy, too thin and they turn to mush.

Step 3. Pour the melted butter evenly over every bit of onion, making sure it reaches the corners and settles between the layers. After years of making this, I give the pan a gentle tap on the counter to help the butter find its way down.

Step 4. Sprinkle the garlic powder, dried thyme, salt, and black pepper across the top, distributing the seasonings so every ring gets some flavor.

Step 5. Toss together your shredded cheddar, Monterey Jack, and grated Parmesan in a bowl, then pile this cheese mixture generously over the onions. Betty always says if you can still see lots of onion peeking through, you need more cheese.

Step 6. Cover the dish loosely with aluminum foil (don’t press it down onto the cheese or it’ll stick) and slide it into the oven for 25 minutes while the onions start to soften and the cheese begins melting.

Step 7. Pull off that foil and let it bake another 10 minutes until the cheese turns golden brown with bubbly, crispy spots all over the top. My family prefers when I let it go an extra couple minutes for maximum golden coverage.

Step 8. Optional but worth it: Flip on your broiler and give the dish 2 to 3 minutes under high heat for an extra-crispy, deeply golden top. Just keep a close eye on it to prevent burning – it goes from perfect to overdone fast.

Step 9. Let the Tennessee Onions rest for about 5 minutes before serving since they come out of the oven hotter than lava. The key I discovered is this cooling time lets the cheese firm up just enough to serve neatly without losing that gooey center everyone loves.

Keeping This Fresh

Store any leftovers in an airtight container in the refrigerator for up to 3 days, though they tend to disappear faster than that around here. The cheese sets up as it cools, but Betty discovered the flavors actually get better overnight as everything melds together. I typically grab a cold piece straight from the fridge for a quick snack, or warm portions in a 350°F oven for about 10 minutes to bring back that melty texture.

For reheating, spread your portion on an oven-safe plate and warm at 350°F until heated through and the cheese softens again, usually 8 to 10 minutes depending on how much you’re reheating. The microwave works if you’re in a hurry (1 to 2 minutes on medium power), but you’ll sacrifice some of that crispy cheese texture on top. Through trial and error, I learned that dotting the top with a small pat of butter before reheating brings back some of that just-baked richness.

This dish doesn’t freeze particularly well because the onions release moisture when thawed, creating a watery mess that doesn’t compare to the fresh version. You can absolutely assemble everything the night before and keep it covered in the fridge, then bake it the next day. Just add 5 to 10 minutes to the covered baking time since you’re starting cold.

Perfect Partners for Tennessee Onions

Grilled steak or burgers – The rich, cheesy onions cut beautifully through char-grilled beef, creating that classic steakhouse pairing Betty served at every summer cookout. Garlic butter steak bites make an especially good match.

BBQ chicken or ribs – Something about the sweet-savory onions alongside tangy, smoky barbecue just works every time on the table.

Simple green salad – Balance all that cheese and butter with crisp greens, cherry tomatoes, and a light vinaigrette to keep your plate from feeling too heavy.

FAQs

Tennessee Onions (Better Than Onion Rings)

Thick slices of sweet Vidalia onions baked with melted butter, three cheeses, and seasonings until golden and bubbly. This easy Southern side dish is ready in 50 minutes and delivers all the comfort of a gratin without the fuss.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

Total Time 50 minutes mins

Servings: 6 portions

Course: Side Dish

Cuisine: American, Southern

Calories: 260

Ingredients Equipment Method Notes

Ingredients

  

• 3 large sweet onions (such as Vidalia) sliced into 1/2-inch rings
• 4 tablespoons unsalted butter melted
• 1.5 cups shredded cheddar cheese
• 1 cup shredded Monterey Jack cheese
• 0.5 cup grated Parmesan cheese
• 1 teaspoon garlic powder
• 0.5 teaspoon dried thyme
• 0.5 teaspoon salt
• 0.25 teaspoon black pepper

Equipment

• 9×13 inch baking dish
• Aluminum foil
• Cheese grater
• mixing bowl

Method

 

1. Preheat oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish.
2. Peel onions and slice into 1/2-inch rings. Arrange in an even layer in the prepared baking dish, separating the rings.
3. Drizzle melted butter evenly over the onions.
4. Sprinkle garlic powder, dried thyme, salt, and black pepper evenly over the onions.
5. In a bowl, toss together cheddar, Monterey Jack, and Parmesan cheeses. Spread cheese mixture generously over the onions.
6. Cover dish with aluminum foil and bake for 25 minutes.
7. Remove foil and bake for an additional 10 minutes, or until cheese is golden and bubbly.
8. Optional: Broil for 2 to 3 minutes for extra crispy top (watch carefully to prevent burning).
9. Let cool for 5 minutes before serving.

Notes

Use sweet onions like Vidalia for best results. Can substitute yellow or red onions. Mix and match cheeses based on what’s available. Even better the next day as leftovers. Don’t skip the resting time as the dish is extremely hot straight from the oven.