If there’s one dish that perfectly captures the heart of Southern comfort food, it’s Tennessee Onions. Rich, cheesy, buttery, and irresistibly simple, this baked onion casserole transforms humble sweet onions into a side dish that often outshines the main course. Whether served at a holiday table, backyard barbecue, or cozy family dinner, Tennessee Onions deliver bold flavor with minimal effort.

This recipe is a beloved Southern classic, known for its layers of sweet onions baked beneath a blanket of melted cheese and seasoned butter. The magic lies in its simplicity—few ingredients, no complicated steps, and a result that feels indulgent and nostalgic all at once.

In this guide, you’ll learn not only how to make Tennessee Onions perfectly every time, but also the history behind the dish, expert tips, variations, and serving ideas that make it endlessly versatile.

What Are Tennessee Onions?

Tennessee Onions are a baked onion casserole made primarily with sliced sweet onions, butter, shredded cheese, and simple seasonings. As the dish bakes, the onions soften and caramelize slightly, releasing their natural sweetness, while the cheese melts into a bubbling, golden topping.

Unlike onion rings or fried onions, this dish celebrates onions in their purest form—soft, savory, and deeply flavorful. It’s often served as a side dish, but many fans admit they’d happily eat it as a main.

Why This Recipe Works

Minimal ingredients with maximum flavor
Naturally sweet onions balance the richness of cheese
Easy to prep ahead of time
Perfect for holidays, potlucks, and weeknight dinners
Naturally gluten-free

This is the kind of recipe that feels passed down through generations—and once you make it, you’ll understand why.

Ingredients

Sweet onions (Vidalia or Walla Walla preferred)
Unsalted butter, melted
Shredded cheddar cheese
Shredded Monterey Jack cheese
Garlic powder
Salt
Black pepper
Dried thyme or parsley (optional)

Instructions

Preheat your oven to 350°F (175°C). Lightly butter a baking dish.
Peel the onions and slice them into thick rings, about ¼ inch thick.
Separate the onion rings and spread them evenly in the prepared baking dish.
Drizzle the melted butter evenly over the onions.
Sprinkle salt, black pepper, and garlic powder evenly across the onions.
Add the shredded cheddar and Monterey Jack cheese in an even layer on top.
Sprinkle dried thyme or parsley over the cheese if using.
Cover the dish loosely with foil and bake for 30 minutes.
Remove the foil and bake an additional 15–20 minutes, until the cheese is bubbly and lightly golden.
Let rest for 5 minutes before serving.

Best Onions to Use for Tennessee Onions

Sweet onions are essential for this dish. Vidalia onions are the traditional choice, prized for their mild flavor and natural sweetness. If unavailable, Walla Walla or Maui onions work beautifully. Yellow onions can be used in a pinch, but the dish will be sharper and less sweet.

Cheese Matters More Than You Think

The combination of cheddar and Monterey Jack provides both flavor and meltability. Sharp cheddar adds depth, while Monterey Jack melts smoothly. You can also experiment with:

Mozzarella for extra stretch
Colby Jack for mild creaminess
Gruyère for a more upscale flavor

Pro Tips for Perfect Tennessee Onions

Slice onions evenly so they cook at the same rate
Don’t skimp on butter—it helps soften and flavor the onions
Cover first, then uncover to avoid burnt cheese
Let the dish rest before serving to set the layers

Variations You’ll Love

Spicy Tennessee Onions
Add crushed red pepper flakes or sliced jalapeños for heat.

Bacon Tennessee Onions
Sprinkle cooked, crumbled bacon between onion layers.

Herb-Forward Version
Add fresh rosemary or thyme for a fragrant twist.

Extra Cheesy
Add a third cheese like mozzarella or provolone.

What to Serve with Tennessee Onions

This dish pairs beautifully with:

Grilled steak or chicken
Baked ham or roast beef
Fried chicken
Barbecue ribs
Thanksgiving turkey

It’s also fantastic alongside simple green vegetables to balance the richness.

Make-Ahead & Storage Tips

Assemble up to 24 hours ahead and refrigerate
Bake fresh before serving
Store leftovers in an airtight container for up to 3 days
Reheat gently in the oven to preserve texture

Cultural Notes & Southern Roots

While the exact origin of Tennessee Onions is debated, the dish reflects classic Southern cooking principles: affordable ingredients, bold flavors, and communal comfort. It’s commonly shared at church suppers, holiday feasts, and family gatherings across the South.

Why Tennessee Onions Are Trending Again

Simple comfort foods are making a comeback, and Tennessee Onions fit perfectly into that revival. With minimal prep and crowd-pleasing appeal, this recipe has become popular on social media, Pinterest, and family blogs alike.

Final Thoughts

Tennessee Onions prove that sometimes the simplest dishes are the most memorable. Sweet, cheesy, and deeply satisfying, this Southern classic deserves a permanent spot in your recipe rotation.

Once you try it, don’t be surprised if it becomes your most requested side dish.