Recipe

Tennessee Onions

Sweet onions baked until tender under a cheesy, buttery topping that turns golden and irresistible.

By Matt Campbell

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4.8

A bubbling baking dish of Tennessee onions with golden melted cheese on top, set on a wooden table with a serving spoon

Tennessee onions are what happens when a pile of sweet onions meets butter and a very enthusiastic amount of cheese, then they all take a nap in the oven together. The onions turn soft and mellow, the cheese goes bubbly and browned in spots, and the whole thing tastes like the side dish version of a warm hug.

This is one of those recipes that looks almost too simple on paper, but the payoff is real. Bring it to a potluck and people will hover near the pan. Make it on a random Tuesday and suddenly your chicken feels like it got invited to a cookout.

Sweet onions, shredded cheddar, shredded mozzarella, butter, and seasonings arranged on a light kitchen counter, ready to prep

Why It Works

Big flavor with small effort: Sweet onions bake into a rich, savory base without any babysitting.
Cheese does the heavy lifting: A cheddar and mozzarella blend gives you sharp flavor plus that gooey pull.
Buttery seasoning hits every layer: Garlic, paprika, and a little thyme make it taste like you did more than you did.
Flexible side dish energy: It works next to BBQ, steak, roasted chicken, or holiday ham, and it is surprisingly good spooned over baked potatoes.

Pairs Well With

Storage Tips

Refrigerate: Cool completely, then cover the baking dish tightly or transfer to an airtight container. Store up to 4 days.

Reheat: For the best texture, reheat in a 350°F oven until hot and bubbly, about 15 to 20 minutes. A microwave works too, but the cheese will stay softer and less crisp on top.

Freeze: You can freeze it, but onions release water as they thaw, so the texture will be a little softer. Freeze in an airtight container up to 2 months. Thaw overnight in the fridge, then reheat uncovered in the oven to help drive off extra moisture.

Common Questions

What are Tennessee onions?

Tennessee onions are a baked sweet onion and cheese casserole made with sliced sweet onions, butter, shredded cheese, and simple seasonings. You will see it shared a lot as a Southern-style, church-cookbook and potluck kind of recipe, especially online. Think French onion soup vibes, but in scoopable side dish form.

Do I need sweet onions?

Sweet onions (Vidalia, Walla Walla, or any local “sweet” variety) give the best mellow flavor. Yellow onions work too, they will just taste a little sharper. If you use yellow onions, you can add 1 teaspoon sugar to nudge the flavor sweeter, then adjust to taste next time if you want more.

Can I make Tennessee onions ahead of time?

Yes. Assemble the dish (onions, seasonings, cheese, butter), cover, and refrigerate up to 24 hours. Bake as directed, adding 5 to 10 minutes if it goes into the oven cold.

Why are my onions watery?

Some onions just carry more moisture. A few fixes: slice a bit thicker (about 1/4 inch), bake uncovered, and let the dish rest 10 minutes before serving so the juices settle. Using freshly shredded cheese also helps, since pre-shredded cheese is often coated with starches that can melt a little less smoothly.

What cheese works best?

I love a mix of sharp cheddar for flavor and mozzarella for melt. Monterey Jack, Colby, provolone, or a little smoked gouda are all excellent swaps. If you want a more savory finish, add a small handful of grated Parmesan on top.

Any easy variations?

Absolutely. Add a pinch of cayenne for heat, swap in pepper jack, or finish with a light sprinkle of Parmesan. If you want a little crunch, add a small handful of buttered panko on top for the last 10 minutes of baking.

Matt Campbell

I have always had a huge passion for the culinary arts, people, working as a team, and so on. I wanted to pursue my love for cooking initially at Virginia Commonwealth University with a culinary arts degree; however, I instead decided to apply myself and acquire more practical skills. My end goal is to eventually open my own restaurant or similar establishment.

Kitchen Essentials

9x13-inch baking dish (or similar 3-quart dish)
Chef’s knife
Cutting board
Mixing bowl (optional, for tossing seasonings)
Measuring spoons
Foil (optional, if you want to prevent over-browning)

I love recipes like this because they feel like a team effort between you and your pantry. You do about five minutes of real work, then the oven takes over and starts making your kitchen smell like you absolutely have your life together. The first time I made Tennessee onions, I kept “taste testing” little forkfuls straight from the pan while pretending I was just checking seasoning. It is a side dish, sure, but it behaves like the main character.