Tennessee Onions: The Easy, Cheesy Casserole You Have To Try


This old-fashioned onion casserole is unlike any side dish you've had before.

Active Time:
10 mins
Total Time:
1 hrs 20 mins

Onions don't get the credit they deserve. They're the backbone of soups, casseroles, and pasta dishes. They're also wonderful chopped or sliced and served raw on salads, sandwiches, even burgers.

But even the most ardent onion fan has probably never heard of Tennessee Onions.

What's in Tennessee Onions?

This onion casserole is made with a handful of simple ingredients: onions, cheese, and butter mainly. Some herbs are added to boost the flavor of the final dish and the rich sauce that forms in the pan as the onions melt and tenderize.

What Do Tennessee Onions Taste Like?

The key to this dish is, obviously, the onions. But not just any onions will do. You need sweet onions, and more specifically, you need sweet Vidalia onions if you can find them.

The Georgia-grown sweet onions are beloved for their naturally sweet taste. They still have a bit of bite, like any onion should, but they're not pungent and assertive. Farmers in Georgia credit the unique soil of the 20-county growing region, centered around, you guessed it, Vidalia, Georgia, for the unique flavor.

So why do Tennessee Onions use Georgie onions? We're really not sure, but we're going to eat it anyway.

Melty cheeses—we use smoked gouda and mild Cheddar—get a bit crispy and blend into the herbs and butter to create a sauce that you better not leave behind. The final dish is a cheesy, tangy-sweet scoop of tender onion slices with browned bits of cheese.

Southern Living Tennessee Onions in the dish ready to serve

Caitlin Bensel; Food Stylist: Torie Cox

Tips for Making Tennessee Onions

This casserole is straightforward, but that doesn't mean there aren't some handy tips to make the final dish better.

  • Slice the onions evenly into rings about 1/2 inch wide.
  • Separate the onion rings out so they cook evenly. Don't leave them nested.
  • No Vidalia onions? Sweet onions like Walla Walla and Texas sweet will work, too.

How To Serve Tennessee Onions

We aren't sure whether to call these onions a side dish or a condiment. So really, we'll treat them as both.

A scoop of these at a potluck or barbecue will be welcomed by all, but we also want to eat them on burgers, atop grilled chicken or steak, or even in between slices of bread for an onion-rich grilled cheese.

More Ways With Onions:


  • Cooking spray

  • 2 1/2 lb. sweet onions (about 3 large onions), sliced crosswise into 1/4-in.-thick slices and separated into 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, cut into 1/4-in.-thick pieces

  • 4 oz. mild Cheddar cheese, shredded (about 1 cup)

  • 4 oz. smoked Gouda cheese, shredded (about 1 cup)


  1. Warm the oven:

    Preheat oven to 350°F. Coat a 13- x 9-inch baking dish with cooking spray.

    Gather your ingredients.

    Southern Living Tennessee Onions ingredients

    Caitlin Bensel; Food Stylist: Torie Cox

  2. Season the onions:

    Place onions in a large bowl. Sprinkle with thyme, parsley, garlic salt, oregano, mustard, and cayenne pepper; toss gently to coat.

    Southern Living Tennessee Onions in a bowl with seasoning

    Caitlin Bensel; Food Stylist: Torie Cox

    Arrange evenly in prepared baking dish.

    Southern Living Tennessee Onions in the baking dish

    Caitlin Bensel; Food Stylist: Torie Cox

  3. Add toppings and bake:

    Arrange butter evenly over onions, and sprinkle with Cheddar and Gouda.

    Southern Living Tennessee Onions with topping

    Caitlin Bensel; Food Stylist: Torie Cox

    Cover with aluminum foil, and bake in preheated oven until onions are soft and sides are bubbly, about 40 minutes.

    Southern Living Tennessee Onions covered with foil

    Caitlin Bensel; Food Stylist: Torie Cox

  4. Finish baking:

    Remove foil. Bake at 350°F until top is golden, about 30 minutes.

    Southern Living Tennessee Onions in the dish after baking

    Caitlin Bensel; Food Stylist: Torie Cox

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