These Tennessee Onions are a beloved Southern side dish that turns sweet onions into something absolutely irresistible through slow baking with butter, cheese, and seasonings. What makes this dish so special is how the onions become incredibly tender and sweet during the long cooking process, while the top develops a golden, bubbly crust of melted cheese. The combination of sweet Vidalia onions, rich butter, and sharp cheese creates a perfect balance of flavors that complements everything from grilled meats to holiday roasts. This recipe has been passed down through Tennessee kitchens for generations, and once you try these melt-in-your-mouth onions, you’ll understand why they’ve become such a cherished part of Southern comfort food tradition.
Serves: 8-10 people as a side dish
Total Time: 1 hour 30 minutes
Active Prep Time: 15 minutes
What You’ll Need
For the Tennessee Onions:
- 4 large sweet onions (Vidalia or Walla Walla), peeled and sliced thick
- 4 tablespoons butter, melted
- 1 cup sharp cheddar cheese, shredded
- 1/2 cup Parmesan cheese, grated
- 1/2 cup mayonnaise
- 1/4 cup sour cream
- 2 cloves garlic, minced
- 1 teaspoon Worcestershire sauce
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper
- 1/4 teaspoon paprika
- 2 tablespoons fresh chives, chopped
- 1/4 cup panko breadcrumbs (optional, for extra crunch)
Preparing the Onions
Preheat your oven to 350 degrees Fahrenheit and generously butter a 9×13 inch baking dish. The butter prevents sticking and adds extra richness to the finished dish.
Peel the onions and slice them into thick rounds, about half an inch thick. Try to keep the rings intact as much as possible – this creates a more attractive presentation and helps the onions hold their shape during the long baking process.
Arrange the onion slices in overlapping layers in your prepared baking dish. Don’t worry about making them perfectly neat – rustic presentation is part of the charm of this homestyle dish. Drizzle the melted butter evenly over all the onion slices, making sure each piece gets some butter.
Making the Cheese Mixture
In a medium bowl, combine the mayonnaise and sour cream. These ingredients create a creamy base that helps bind everything together while adding richness and tang. Whisk them together until smooth.
Add the minced garlic, Worcestershire sauce, salt, pepper, and paprika to the mayonnaise mixture. Stir until all the seasonings are evenly distributed. The Worcestershire sauce adds a subtle savory depth that enhances the natural sweetness of the onions.
Fold in three-quarters of the shredded cheddar cheese and half of the Parmesan cheese, reserving the rest for the top. This ensures you get cheese throughout the dish, not just on the surface.
Assembling the Dish
Spread the cheese mixture evenly over the arranged onions, using a spoon or offset spatula to cover as much surface area as possible. Don’t worry if some onion pieces peek through – this adds to the rustic appeal.
Sprinkle the remaining cheddar and Parmesan cheeses over the top, followed by the panko breadcrumbs if using. The breadcrumbs create an extra golden, crunchy top layer that provides nice textural contrast to the tender onions beneath.
The Slow Baking Process
Cover the baking dish with aluminum foil and place it in the preheated oven. Bake covered for 45 minutes. This initial covered cooking allows the onions to steam and become incredibly tender while the flavors meld together.
After 45 minutes, remove the foil and continue baking for another 30 to 45 minutes, or until the top is golden brown and bubbly. The onions should be fork-tender and the cheese mixture should be set and lightly browned on top.
During the uncovered baking time, the moisture evaporates and the top develops that signature golden crust that makes Tennessee Onions so appealing. Keep an eye on the dish during the last 15 minutes to prevent over-browning.
Finishing Touches
Remove the dish from the oven and let it rest for about 10 minutes before serving. This resting time allows the cheese mixture to set up slightly and makes serving easier. The onions will be very hot, so this cooling period also prevents burnt tongues.
Just before serving, sprinkle the fresh chopped chives over the top. The bright green color and mild onion flavor of the chives provide a fresh contrast to the rich, baked onions and add a pop of color to the golden-brown dish.
Serving Suggestions
Tennessee Onions are the perfect side dish for almost any Southern or comfort food meal. They pair beautifully with grilled or roasted meats, especially beef, pork, or chicken. The sweet, cheesy onions also complement barbecue dishes wonderfully.
These onions are a natural fit for holiday tables, potluck dinners, and family gatherings. They’re substantial enough to satisfy vegetarians when served alongside other vegetables and starches, yet they won’t overshadow your main course.
Storage and Reheating Tips
Leftover Tennessee Onions keep well in the refrigerator for up to 4 days. Cover the dish tightly with plastic wrap or transfer to an airtight container. The flavors actually develop and improve after a day or two.
To reheat, cover with foil and warm in a 325-degree oven for about 20 minutes, or until heated through. You can also reheat individual portions in the microwave, though the oven method better preserves the texture of the cheese topping.
Variations and Tips
For extra flavor, try adding crispy bacon pieces to the cheese mixture or sprinkling them on top before the final bake. Caramelized mushrooms also make an excellent addition for mushroom lovers.
Make sure to use sweet onions like Vidalia or Walla Walla for the best results. Regular yellow onions will work but may be more pungent and less sweet. The natural sugars in sweet onions caramelize beautifully during the long baking process, creating the signature flavor that makes Tennessee Onions so special.
