If you are looking for the ultimate southern comfort side dish, this Tennessee Onions Recipe is a cheesy, savory masterpiece. Made with sweet Vidalia onions and a blend of three cheeses, it transforms simple ingredients into a crowd-pleasing casserole that pairs perfectly with any main course.
Why You Will Love This Recipe
This Tennessee Onions Recipe is a true staple for anyone who loves simple, versatile comfort food. It uses basic pantry staples and a single 13″ x 9″ baking dish to create a side dish that is surprisingly rich and flavorful. The combination of sweet Vidalia onions, sharp cheddar, creamy mozzarella, and nutty Parmesan creates a melty, caramelized texture that is hard to resist. Whether you need a last-minute addition to a holiday dinner or a savory topping for your favorite meats, these onions deliver maximum flavor with minimal effort.
Ingredients
- Cooking spray
- 2 1/2 lb. sweet Vidalia onions (about 3 large or 4 medium), peeled
- 1 tsp. dried parsley
- 1 tsp. dry mustard
- 1 tsp. garlic powder
- 3/4 tsp. seasoned salt
- 1/2 tsp. dried oregano
- 1/2 tsp. kosher salt
- 1/4 tsp. cayenne pepper
- 1/4 tsp. freshly ground black pepper
- 1 cup shredded mozzarella
- 1 cup shredded sharp cheddar
- 1/2 cup finely grated Parmesan
- 4 Tbsp. unsalted butter, cut into cubes
- 1/2 cup low-sodium vegetable broth
- Finely chopped fresh parsley, for serving
Step-by-Step Instructions
- Arrange an oven rack in the center position and preheat your oven to 350°. Lightly grease a 13” x 9” baking dish with cooking spray.
- Place a peeled onion on its side on a cutting board. Using vertical slices, cut the onion into rounds approximately 1/4″ thick. Separate the rounds into individual rings. Restack the rings, starting from the largest piece and moving to the smallest to mimic the original shape of the onion rounds, and place them in the prepared dish. Repeat this process with the remaining onions until you have about 4 stacks.
- In a small bowl, combine the dried parsley, dry mustard, garlic powder, seasoned salt, oregano, kosher salt, cayenne, and black pepper. Stir until the spice mix is homogenous.
- In a separate medium bowl, toss together the shredded mozzarella, sharp cheddar, and grated Parmesan.
- Sprinkle the seasoning mixture evenly over the onion stacks and gently toss to ensure they are coated. Dot the tops of the onions with the butter cubes. Pour the vegetable broth into the bottom of the pan and cover the dish tightly with aluminum foil.
- Bake the onions for 75 to 90 minutes until they are tender and the centers can be easily pierced with a fork or metal cake tester.
- Remove the dish from the oven and discard the foil. Sprinkle the cheese mixture generously over the onions.
- Return the dish to the oven and bake until the cheese is melted and bubbling around the edges, which should take about 5 to 7 minutes.
- Turn on the broiler and broil for 1 to 2 minutes, watching closely, until the cheese is browned in a few spots. Top with fresh parsley and serve immediately.
Expert Tips / Pro Tips
To get the best results with your Tennessee Onions Recipe, focus on even slicing. Keeping the onion rings to a consistent 1/4″ thickness ensures that every piece cooks at the same rate, preventing some rings from being crunchy while others are mushy. It is also vital to separate the rings before restacking them; this allows the seasonings and the vegetable broth to penetrate the layers for a more flavorful result.
One of the most important tips is to use freshly shredded cheese. Pre-shredded cheese from a bag is coated in anti-caking agents that prevent it from melting smoothly. For that perfect, gooey cheese pull, take the extra five minutes to grate your own cheddar and mozzarella. Finally, do not overcook the cheese at the end—once it is bubbling and slightly browned, pull it out to keep it from becoming rubbery.
If you cannot find Vidalia onions, you can substitute them with other sweet varieties like Walla Walla, Texas Sweet, or Maui onions. In a pinch, standard yellow onions will work, though the final dish will be less naturally sweet. For the cheese, feel free to experiment with Monterey Jack for extra creaminess or Gruyère for a more sophisticated, nutty flavor profile.
If you want to change the flavor profile, you can swap the parsley and oregano for Italian seasoning. For those who enjoy more heat, increase the cayenne pepper or add a dash of red pepper flakes. If you do not have seasoned salt, you can make your own by increasing the kosher salt to 1 1/4 tsp and adding 1/4 tsp each of ground paprika and granulated sugar.
Serving Suggestions
This Tennessee Onions Recipe is incredibly versatile. It shines as a side dish alongside hearty mains like pot roast, grilled chicken, or smoked pulled pork. However, these cheesy onions also make a fantastic topping. Try piling them onto a gourmet burger, layering them into a chicken sandwich, or even adding them to a grilled cheese sandwich to take your lunch to the next level.
If you have leftovers, store them in an airtight container in the refrigerator for up to 3 days. Because of the high moisture content in the onions and the dairy, this dish does not freeze particularly well, as the texture of the onions can become mushy upon thawing.
To reheat, the oven is your best friend. Place the onions in an oven-safe dish, cover with foil, and warm at 350° until the cheese is melted and the onions are heated through. You can also use a microwave for individual portions, heating in 30-second intervals, though the cheese may not be as bubbly as it was when fresh.
Nutrition Information
| Metric | Amount Per Serving |
| Calories | 284 kcal |
| Servings | 6 – 8 |
| Prep Time | 20 mins |
| Total Time | 2 hrs 30 mins |
FAQ
What are the best onions to use for this recipe?
Vidalia onions are the preferred choice because of their high sugar content and mild flavor. If they are not in season, look for other sweet onion varieties like Walla Walla or Maui onions.
Can I make Tennessee onions ahead of time?
You can prep the onions and the seasoning mix ahead of time, but for the best texture, it is recommended to bake them fresh. If you must make them ahead, follow the instructions through the first bake, then add the cheese and do the final melt/broil right before serving.
Is this dish spicy because of the cayenne pepper?
No, the small amount of cayenne pepper is intended to provide a well-rounded savory depth rather than heat. It balances the sweetness of the onions without making the dish “hot.”
Why do I need to add water or broth to the pan?
Adding liquid to the bottom of the pan and covering it with foil creates steam. This helps the onions soften and caramelize properly during the long baking process without drying out or burning.
Tennessee Onions Recipe
Ingredients
Method
- Preheat your oven to 350°F and position a rack in the center. Lightly grease a 13×9-inch baking dish with cooking spray.
- Slice the onions into 1/4-inch thick rounds. Separate the rounds into individual rings and restack them from largest to smallest in the prepared dish to mimic their original shape.
- In a small bowl, whisk together the dried parsley, dry mustard, garlic powder, seasoned salt, dried oregano, kosher salt, cayenne, and black pepper. In a separate medium bowl, toss the mozzarella, cheddar, and Parmesan together.
- Sprinkle the seasoning mixture over the onions and gently toss to coat. Dot the onions with the butter cubes and pour the vegetable broth into the bottom of the pan.
- Cover the dish tightly with aluminum foil and bake for 75 to 90 minutes, or until the centers of the onions are soft and easily pierced with a fork.
- Remove the foil and generously sprinkle the cheese mixture over the onions. Return to the oven and bake for 5 to 7 minutes until the cheese is melted and bubbling.
- Turn the oven to broil and cook for 1 to 2 minutes until the cheese is browned in spots. Garnish with fresh parsley and serve immediately.