Cheesy & Melty Tennessee Onions
Add Preferred SourceTennessee Onions are the kind of side dish people don’t expect to love as much as they do. Baked until soft, buttery, and bubbling, this dish turns humble onions into something rich, savory, and completely irresistible. I love this side dish, and if you’re an onion fan, I bet you’ll love it, too!
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I’m not sure where this dish came from, but you can’t go wrong with sweet onions, piles of cheese, and just the right hit of spice.
This is comfort cooking at its best. The onions melt into silky layers, the top turns golden and gooey, and every scoop delivers deep, cozy flavor without a lot of effort. It’s easy to prep and generous enough to feed a crowd; these onions pair beautifully with grilled meats, holiday roasts, or weeknight dinners. I especially love it with Easter ham. Yum!
Ingredients
- Cooking spray – Just enough to lightly coat the baking dish so nothing sticks as the onions soften and caramelize.
- Sweet onions – Vidalia or Walla Walla onions work best. Yellow onions work in a pinch, but won’t be as sweet.
- Dried thyme – Dried thyme goes a long way. Measure carefully, or it’ll overpower the dish.
- Dried parsley flakes – Fresh parsley won’t work here—it needs the long baking time to rehydrate.
- Garlic salt – Not garlic powder, or you’ll need to add extra salt separately.
- Dried oregano – Just enough to add warmth without pushing this into Italian territory.
- Dry mustard – Ground mustard powder. Don’t substitute with prepared mustard—it’ll make the dish watery.
- Cayenne pepper – Add more if you like extra heat.
- Salted butter – Cut into small pieces so it melts evenly over the onions. You can use unsalted butter, but I’d season the onions a bit more before baking.
- Mild white cheddar cheese – I recommend shredding your own cheese with a rotary grater. Pre-shredded cheese is coated with anti-caking agents that make it gritty and prevent smooth melting.
- Smoked gouda cheese – Regular Gouda works if you can’t find smoked, but you’ll lose the smoky depth. Power through the grating with your rotary grater.
How To Make Tennessee Onions
Scroll down for the full recipe card with exact measurements and printable instructions.
Preheat the oven to 350°F and coat a 9×13-inch baking dish with cooking spray. A ceramic or glass baking dish works best here because it holds heat evenly.
Slice the onions crosswise into ¼-inch-thick rings. Separate the rings gently with your hands so they cook evenly and don’t clump together.
Add the onion rings to a large mixing bowl. Sprinkle in the thyme, parsley, garlic salt, oregano, dry mustard, and cayenne pepper. Toss everything together using clean hands or a large silicone mixing spoon until the onions are evenly coated with seasoning.
Transfer the seasoned onions to the prepared baking dish and spread them into an even layer. They will look full at first, but they cook down significantly. Dot the onions with the pieces of butter, spacing them evenly across the dish so the butter melts into every layer.
Sprinkle the shredded Cheddar and smoked Gouda evenly over the top. Using freshly shredded cheese helps it melt more smoothly than pre-shredded.
Cover the dish tightly with aluminum foil and bake for about 40 minutes, until the onions are soft and bubbling around the edges.
Remove the foil and return the dish to the oven. Bake for another 25 to 30 minutes, until the cheese is melted, golden, and lightly browned on top.
Let the onions rest for about 5 minutes before serving so they set slightly and scoop cleanly.
Chef Jenn’s Recipe Notes
- Don’t slice the onions too thin; you want them to hold together and not turn into mush.
- Sweet onions are key. I’ve tested this recipe with both Spanish onions and Vidalia onions, and they’re both delish.
- Shred your own cheese for the best melting and texture. I use my rotary grater All.The.Time. It powers through cheese blocks easily and saves my hand from all that manual grating.
- If the top browns too quickly, tent the dish loosely with foil for the last few minutes.
Make It A Meal
Serve Tennessee Onions alongside roast beef, Garlic-Lime Grilled Chicken or even salmon. They’re also excellent next to meatloaf or my favorite Smothered Pork Chops.
Storage
Store leftover Tennessee Onions in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven until warmed through.
Tennessee Onions
Ingredients
- cooking spray
- 2 ½ pounds sweet onions sliced into ¼-inch rings
- 1 teaspoon dried thyme
- 1 teaspoon dried parsley flakes
- 1 teaspoon garlic salt
- ½ teaspoon dried oregano
- ½ teaspoon dry mustard
- ¼ teaspoon cayenne pepper
- ¼ cup salted butter cut into pieces
- 4 ounces white Cheddar cheese shredded
- 4 ounces smoked Gouda cheese shredded
Instructions
- Preheat the oven to 350°F and coat a 9×13-inch baking dish with cooking spray. A ceramic or glass baking dish works best here because it holds heat evenly.
- Slice the onions crosswise into ¼-inch-thick rings. Separate the rings gently with your hands so they cook evenly and don’t clump together.
- Add the onion rings to a large mixing bowl. Sprinkle in the thyme, parsley, garlic salt, oregano, dry mustard, and cayenne pepper. Toss everything together using clean hands or a large silicone mixing spoon until the onions are evenly coated with seasoning.
- Transfer the seasoned onions to the prepared baking dish and spread them into an even layer. They will look full at first, but they cook down significantly.
- Dot the onions with the pieces of butter, spacing them evenly across the dish so the butter melts into every layer.
- Sprinkle the shredded Cheddar and smoked Gouda evenly over the top. Using freshly shredded cheese helps it melt more smoothly than pre-shredded.
- Cover the dish tightly with aluminum foil and bake for about 40 minutes, until the onions are soft and bubbling around the edges.
- Remove the foil and return the dish to the oven. Bake for another 25 to 30 minutes, until the cheese is melted, golden, and lightly browned on top.
- Let the onions rest for about 5 minutes before serving so they set slightly and scoop cleanly.
Video
Notes
Chef Jenn’s Recipe Notes
- Don’t slice the onions too thin; you want them to hold together and not turn into mush.
- Sweet onions are key. I’ve tested this recipe with both Spanish onions and Vidalia onions, and they’re both delish.
- Shred your own cheese for the best melting and texture. I use my rotary grater All.The.Time. It powers through cheese blocks easily and saves my hand from all that manual grating.
- If the top browns too quickly, tent the dish loosely with foil for the last few minutes.
Nutrition
A Note on Nutritional Information
Nutritional information for this recipe is provided as a courtesy and is calculated based on available online ingredient information. It is only an approximate value. The accuracy of the nutritional information for any recipe on this site cannot be guaranteed.
