Tennessee Onions are an easy Southern side dish made with tender yellow onions, buttery seasoning, and layers of melty cheddar, mozzarella, Monterey Jack, and Parmesan cheese. This cheesy Tennessee onion casserole is simple to make with just a few ingredients and is the perfect side for family dinners, holiday meals, backyard barbecues, or your next potluck.

Tennessee Onions Recipe

If you’ve never tried Tennessee Onions before, you’re in for a treat. This simple Southern side dish transforms humble yellow onions into a rich, cheesy casserole that’s packed with flavor. As the onions bake, they become tender and sweet while layers of melty cheese and butter create an irresistible golden topping.

With just a handful of simple ingredients and almost no prep work, this Tennessee onions recipe is perfect for busy weeknights, holiday dinners, or your next potluck. Whether you’re serving it alongside steaks, pork chops, burgers, or barbecue chicken, this cheesy onion casserole is guaranteed to disappear fast. It will be your new favorite way to eat onions!

Why You’ll Love This Tennessee Onions Recipe

• Only a few pantry staples and simple ingredients.
• Rich, buttery flavor with lots of melty cheese.
• The onions become perfectly sweet and tender while baking.
• Easy enough for a weeknight family dinner but impressive enough for holiday meals.
• A wonderful side dish for everything from hot dogs to pork chops and burgers.
• Great for your next summer BBQ or backyard barbecue.

What Are Tennessee Onions?

Tennessee Onions are a classic Southern onion dish made by layering thick slices of onions in a baking dish, seasoning them, covering them with several types of cheese, and finishing everything with melted butter. As they bake, the onions soften and become incredibly sweet while the cheese turns bubbly and golden. This Fabulous Tennessee Onion Bake is also called a Tennessee Onion Casserole.

The beauty of Tennessee onions is that they take an inexpensive vegetable and turn it into the star of the show.

Tools You’ll Need

• 9 x13-inch casserole dish or prepared baking dish
• Non-stick cooking spray
• Sharp knife
• Cutting board
• Measuring spoons
• Aluminum foil

Ingredients

These ingredients are all very common and easily found in any grocery store.

• Yellow onions
• Salt
• Black pepper
• Garlic powder
• Oregano
• Cheddar cheese
• Mozzarella cheese
• Monterey Jack cheese
• Parmesan cheese
• Butter (salted or unsalted butter works – just depending on your preference)

Ingredient Notes

Yellow onions are my favorite choice for Cheesy Onions because they become wonderfully sweet during baking. Sweet onions, including sweet Vidalia onions or Walla Walla onions, also work beautifully if you want an even milder flavor profile. You can even make a “Vidalia onion casserole” using this same recipe.

Regular onions work just fine, but avoid using a red onion unless you enjoy its stronger bite. The goal is a tender, sweet onion with just a bit of bite left after baking.

For the best flavor, buy blocks and shred your own cheese. Freshly shredded cheese melts better than the pre-shredded kind and creates the perfect cheesy combination. Sharp cheddar adds extra flavor, while mild cheddar creates a creamier finish. If you’d like a little heat, swap the Monterey Jack for pepper jack. It doesn’t really matter what type of cheese you use as long as you use lots of cheese!

How to Make Tennessee Onions

1. Preheat your oven to 350 degrees F.
2. Lightly coat a prepared baking dish with non-stick cooking spray.
3. Peel away the papery skins from the onions and slice them into ⅓ to ½-inch onion rings. I have a whole tutorial on cutting onions here.
4. Separate the rings and spread them evenly across the bottom of the baking dish.

5. Sprinkle the onions with the salt, black pepper, garlic powder, and oregano.
6. Evenly sprinkle the cheddar cheese, mozzarella cheese, Monterey Jack, and Parmesan cheese over the top of the onions.
7. Drizzle the melted butter evenly across the cheese.
8. Cover the dish tightly with aluminum foil and bake in the preheated oven for 30 minutes, until the onions have softened.

9. Remove the foil and continue baking for another 30 minutes, or until the cheese is melted, bubbly, and lightly golden.
10. Remove from the oven and serve immediately.

Tips for the Best Tennessee Onion Bake

• Slice the onions evenly so they cook at the same rate.
• Freshly shredded cheese melts much better than packaged shredded cheese.
• Don’t skip covering the casserole during the first half of baking. It helps soften the onions without over-browning the cheese.
• If you’d like a little extra color, broil for 1 to 2 minutes at the end, watching carefully.
• The hardest part is waiting for it to cool enough to eat!

Variations

This simple dish is easy to customize.

• Add a pinch of cayenne pepper or Cajun seasoning for a punch of flavor.
• Replace the oregano with fresh herbs or parsley flakes.
• Try an Italian blend cheese instead of the mozzarella and Monterey Jack.
• Drizzle with a little olive oil instead of part of the butter if you prefer.
• Add a sprinkle of garlic salt in place of some of the regular salt for even more garlic flavor.

What to Serve with Tennessee Onions

This versatile onion dish pairs well with almost any main course.

Serve it with:

• Pork chops
• Grilled chicken
• Meatloaf
• Steak
• Hot dogs
• Burgers (it’s even delicious on top of a burger!)
• Pulled pork

It’s also a great addition to holiday meals or a backyard barbecue spread alongside baked beans, potato salad, and a green salad.

Frequently Asked Questions

Can I use sweet onions instead of yellow onions?

Absolutely! Sweet onions, especially sweet Vidalia onions or Walla Walla onions, make an excellent Tennessee onion casserole because they become incredibly tender and sweet during baking.

Can I make this ahead?

Yes. Assemble the casserole, cover, and refrigerate for up to one day before baking. Let it sit at room temperature while the oven preheats.

How do I store leftovers?

Store leftovers in an airtight container in the refrigerator for 3-4 days.

How do I reheat Tennessee Onions?

Reheat individual portions in the microwave or warm larger portions in a 350-degree oven until heated through.

Can I cook this in a pizza oven?

A pizza oven generally cooks too hot for this recipe. A conventional oven at 350 degrees F produces the best results by allowing the onions to slowly soften while the cheese melts perfectly.

More Favorite Side Dishes

• Sweet Honey Cornbread Recipe (Baking Dish or Skillet)
• Cream Cheese Corn (Easy Casserole Recipe!)
• Southern Butter Beans Recipe (Lima Beans)
• Easy Green Beans with Bacon & Brown Sugar
• Crockpot Funeral Potatoes (Cheesy Potato Casserole)