Name: Tennessee Onions Recipe
Prep time: 20 min
Cook time: 1 h 15 min
Total time: 1 h 35 min
Cuisine: Southern American
Ingredients: 3 pounds Vidalia or sweet onions (about 4 large), cut crosswise into 1/4-inch-thick slices; 1 1/2 teaspoons kosher salt; 1 teaspoon dry mustard powder; 1 teaspoon garlic powder; 1 teaspoon smoked paprika; 1/4 teaspoon cayenne pepper (optional); 4 ounces mild cheddar cheese, shredded (about 1 cup), divided; 4 ounces smoked Gouda or cheddar cheese, shredded (about 1 cup), divided; 1 1/4 ounces grated Parmesan cheese (about 1/3 cup store-bought grated); Cooking spray; 4 tablespoons (1/2 stick) unsalted butter, diced; 2 tablespoons finely chopped fresh parsley leaves, for garnish (optional)

Jump to Recipe

Tennessee Onions are an irresistible celebration of sweet Vidalia onions layered with a symphony of cheeses and spices, baked to bubbly, golden perfection. This dish captures the Southern charm with flavors that are rich, smoky, and comforting — perfect for those moments when you want something that feels both indulgent and homey. Every bite offers tender, caramelized onions with a crispy cheese crust that makes Tennessee Onions a memorable standout for any occasion, from family dinners to holiday feasts.

Ingredients You’ll Need

Gathering the right ingredients for Tennessee Onions is delightfully simple, yet each one plays an essential role in building layers of flavor and texture that define this classic dish.

Cooking spray: Helps ensure your baking dish is perfectly greased to prevent sticking without adding extra fat.

3 pounds Vidalia or sweet onions (about 4 large), sliced: The sweet onions bring natural caramel-like sweetness that melts beautifully when baked.
1 1/2 teaspoons kosher salt: Essential for enhancing the onions’ sweetness and seasoning the entire dish.

1 teaspoon dry mustard powder: Adds a subtle tangy undertone that complements the cheeses and spices.
1 teaspoon garlic powder: Brings warmth and depth without overpowering the delicate onion flavor.

1 teaspoon smoked paprika: Introduces a smoky aroma that infuses the layers with richness.
1/4 teaspoon cayenne pepper (optional): For a touch of heat that livens up the mellow sweetness.
4 ounces mild cheddar cheese, shredded (about 1 cup), divided: Offers creamy, mellow cheesiness that helps bind the onions together.

4 ounces smoked Gouda or cheddar cheese, shredded (about 1 cup), divided: Adds a smoky depth and smooth texture when melted.
1 1/4 ounces grated Parmesan cheese (about 1/3 cup): Sprinkled on top for a nutty, golden crust that’s simply irresistible.
4 tablespoons unsalted butter, diced: Binds and enriches the dish with luscious buttery flavor.

2 tablespoons finely chopped fresh parsley leaves (optional): Freshens the finished dish with a pop of color and herbaceous brightness.

How to Make Tennessee Onions

Step 1: Prep and Season the Onions

Start by heating your oven to 350ºF and lightly spraying your baking dish. Slice those glorious Vidalia onions into 1/4-inch-thick rings—the thickness ensures they hold together yet become tender as they bake. Toss them in a large bowl with kosher salt, dry mustard, garlic powder, smoked paprika, and a hint of cayenne if you like a little kick. This seasoning mixture is the foundation that transforms simple onions into the signature Tennessee Onions flavor bomb.

Step 2: Layer the Cheese and Onions

Lay half the onion rings in an even layer in your prepared dish, creating a solid base. Next, scatter half the shredded mild cheddar and smoky Gouda evenly over the onions. These two cheeses melt into a silky blanket that enhances the onions’ creaminess, making each bite rich and luscious.

Step 3: Add the Remaining Ingredients

Repeat the layering with the remaining onions and cheeses, then sprinkle the Parmesan cheese over the top for a savory, nutty finish. Dot the entire dish with diced butter—these little pockets of butter melt down as the dish bakes, adding richness and helping the cheese to develop a beautifully browned crust.

Step 4: Bake to Perfection

Cover your baking dish with foil to keep moisture in and bake for about 45 minutes. This allows the onions to soften and the casserole to bubble with cheesy goodness. Remove the foil and continue baking for approximately 30 minutes more until the cheese is golden and bubbly with enticing browned spots. If you’re using parsley, sprinkle it over just before serving to add freshness and a splash of vibrant green color.

How to Serve Tennessee Onions

Garnishes

While the finely chopped fresh parsley is a classic, bright garnish that adds a little visual pop and herbal note, you can also try a sprinkle of crispy fried onions or a dash of extra smoked paprika to emphasize the smoky flavors. A little cracked black pepper on top just before serving can add an inviting peppery aroma and bite.

Side Dishes

Tennessee Onions pair wonderfully with hearty, rustic sides. Think creamy mashed potatoes, roasted meats, or grilled sausages that balance the softness and savoriness of the cheesy onions perfectly. A crisp green salad with a tangy vinaigrette would also bring a refreshing contrast to the richness.

Creative Ways to Present Tennessee Onions

For a fun twist, try spooning Tennessee Onions over toasted baguette slices as a savory appetizer or use them as a decadent topping for burgers or steak sandwiches. You could even serve them alongside grilled chicken tacos for an unexpected, smoky-sweet layer that elevates every bite.

Make Ahead and Storage

Storing Leftovers

If you happen to have any leftovers, Tennessee Onions store beautifully in an airtight container in the refrigerator for up to 3 days. The flavors deepen overnight, making the dish even more flavorful when reheated.

Freezing

You can freeze Tennessee Onions, although cheese-heavy dishes sometimes change texture slightly after thawing. Wrap the baked casserole tightly with foil and plastic wrap, and freeze for up to 2 months. Thaw overnight in the fridge before reheating for best results.

Reheating

Reheat your Tennessee Onions in a 350ºF oven uncovered for about 15-20 minutes until warmed through and the cheese regains its melty appeal. Avoid microwaving if possible to keep the cheese texture just right and the onions tender but not mushy.

FAQs

Can I use other types of onions for Tennessee Onions?

While Vidalia onions are preferred for their sweetness, you can substitute other sweet onions such as Walla Walla or Maui onions. Avoid regular yellow onions, as they are more pungent and less sweet.

Is the cayenne pepper necessary for the recipe?

The cayenne pepper is optional and adds a subtle heat that complements the sweetness and smokiness, but you can leave it out if you prefer a milder dish.

Can I make Tennessee Onions vegetarian?

Absolutely! This recipe is naturally vegetarian, especially if you ensure your cheeses do not contain animal-based rennet, making it a great choice for a meat-free meal.

What can I substitute for smoked Gouda?

If you don’t have smoked Gouda, you can use smoked cheddar, fontina, or even a mild smoked mozzarella to maintain that lovely smoky flavor and gooey texture.

How do I get the cheese on top nicely browned?

Removing the foil for the last 30 minutes of baking allows the cheese to brown and bubble beautifully. For an extra crispy top, you can briefly broil for 1-2 minutes but watch carefully to avoid burning.

Final Thoughts

Tennessee Onions truly feel like a warm embrace from Southern cooking. Whether you’re sharing this indulgent, cheesy onion dish with family or introducing friends to its irresistible charm, it’s hard not to fall in love with every tender, smoky, flavorful bite. Give Tennessee Onions a try soon—you might just find your new favorite comfort food!

Tennessee Onions Recipe

★★★★★

5.1 from 10 reviews

Author: Mariam
Total Time: 1 hour 35 minutes

Yield: 6 to 8 servings 1x
Diet: Vegetarian

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Description

Tennessee Onions is a savory casserole featuring sweet Vidalia onions layered with a blend of mild cheddar, smoked Gouda, and Parmesan cheeses, seasoned with spices and baked to bubbling perfection. This comforting southern-style dish combines tender, flavorful onions with a rich cheesy topping, perfect as a hearty side or a flavorful vegetarian main.

Instructions

Prepare the onions and seasoning: Heat the oven to 350ºF. Lightly coat a 9×13-inch baking dish with cooking spray. Separate the 3 pounds of sliced Vidalia onions into rings and place them in a large bowl. Add 1 1/2 teaspoons kosher salt, 1 teaspoon dry mustard powder, 1 teaspoon garlic powder, 1 teaspoon smoked paprika, and 1/4 teaspoon cayenne pepper (if using). Toss well to evenly coat all onion rings with the seasoning.
Layer the first half of onions and cheese: Arrange half of the seasoned onion rings in an even layer in the prepared baking dish. Sprinkle evenly with 2 ounces each of shredded mild cheddar and shredded smoked Gouda cheeses (about 1/2 cup of each).
Add the remaining onions and top with cheeses and butter: Arrange the remaining onion rings on top of the first layer. Sprinkle with the remaining 2 ounces each of mild cheddar and smoked Gouda. Evenly sprinkle 1 1/4 ounces grated Parmesan cheese over the top. Scatter 4 tablespoons diced unsalted butter across the surface to add richness.

Bake and finish: Cover the baking dish tightly with aluminum foil and bake in the preheated oven until the onions are softened and the casserole is bubbling, about 45 minutes. Remove the foil and bake uncovered for an additional 30 minutes, or until the cheese on top is melted and browned in spots. Remove from oven and, if desired, sprinkle 2 tablespoons finely chopped fresh parsley leaves over the casserole before serving.

Notes

Vidalia or other sweet onions work best for a naturally sweet flavor; avoid sharper onion varieties.
Cayenne pepper is optional and can be omitted if you prefer no heat.

The cheeses can be substituted with other mild and smoked cheese blends based on preference.
This casserole can be prepared ahead of time and baked just before serving.
For a richer flavor, let the casserole rest for a few minutes after baking to allow flavors to meld.