Tennessee Onions is a classic onion casserole that stands out from any other side dish you’ve ever tried. Onions often go unappreciated, even though they are the foundation of soups, casseroles, and pasta dishes. Whether chopped or sliced, they add flavor when served raw on salads, sandwiches, and burgers.
However, even the biggest onion enthusiasts may not be familiar with Tennessee Onions. This creamy, cheesy casserole is much more than the sum of its ingredients. Give it a try, and you’ll see why it’s a favorite.
Once you learn how to make Tennessee Onions, you’ll want to keep the recipe close by. It’s bound to become a staple at every family gathering from now on.
What Goes Into Tennessee Onions?
This onion casserole is a breeze to whip up, with just a few key ingredients. Here’s what’s in store:
- Onions: Specifically, you’ll want Vidalia onions—no substitutes.
- Cheese: A mix of smoked Gouda and mild Cheddar that melts beautifully, gets a little crispy, and mingles with the herbs and butter to create a sauce you won’t want to leave behind.
- Butter: Essential for making a rich, cheesy sauce that envelops the onions.
- Herbs and Spices: These are added to enhance the flavors and complement the rich sauce that forms as the onions soften and meld together.
How Do Tennessee Onions Taste?
The star of this dish is the onion, but not just any onion will do. Sweet onions are a must, and if possible, opt for sweet Vidalia onions.
These onions, grown in Georgia, are famous for their naturally sweet flavor. They still offer a slight bite, as any good onion should, but they’re mild rather than sharp. Georgia farmers attribute the unique taste to the special soil found in the 20-county region surrounding Vidalia, Georgia.
So, why are Tennessee Onions made with Georgia-grown onions? We’re not entirely sure, but one thing’s for certain: the end result is delicious. Expect a cheesy, tangy-sweet serving of tender onion slices with crispy, golden bits of cheese.
Our Tips for Perfect Tennessee Onions
This casserole is simple, but a few tips can take it to the next level:
- Slice the onions into uniform 1/4-inch rings.
- Separate the rings so they cook evenly—no nested onions here!
- If you can’t find Vidalia onions, other sweet varieties like Walla Walla or Texas Sweet will work just as well.
Serving Suggestions for Tennessee Onions
These onions are versatile enough to serve as either a side dish or a condiment.
They’re a hit at potlucks and barbecues, but you can also pile them on burgers, grilled chicken, or steak. For a twist, try them in an onion-packed grilled cheese sandwich.
Print
Tennessee Onions
Ingredients
- Cooking spray
- 2 1/2 lb. sweet onions (approximately 3 large onions), sliced into 1/4-inch-thick rings
- 1 tsp. dried thyme
- 1 tsp. dried parsley flakes
- 1 tsp. garlic salt
- 1/2 tsp. dried oregano
- 1/2 tsp. dry mustard
- 1/4 tsp. cayenne pepper
- 1/4 cup salted butter, sliced into 1/4-inch-thick pieces
- 4 oz. mild Cheddar cheese, shredded (around 1 cup)
- 4 oz. smoked Gouda cheese, shredded (around 1 cup)
Instructions
- Preheat the oven: Set your oven to 350°F and coat a 13 x 9-inch baking dish with cooking spray.
- Season the onions: In a large bowl, combine the onion slices with thyme, parsley, garlic salt, oregano, mustard, and cayenne pepper. Gently toss until the onions are evenly coated with the seasoning.
- Transfer to baking dish: Spread the seasoned onions evenly across the prepared baking dish.
- Add toppings and bake: Distribute the butter pieces evenly over the onions, then sprinkle the shredded Cheddar and Gouda cheeses on top. Cover the dish with aluminum foil and bake in the preheated oven for about 40 minutes, or until the onions are tender and the edges are bubbling.
- Finish baking: Remove the foil and continue baking at 350°F for an additional 30 minutes, or until the top is golden and bubbly.