The Incredible Casserole Recipe You'll Want To Try ASAP

Made with Vidalia or sweet onions, this incredibly easy casserole recipe puts onions front and center. Tennessee onions are tasty enough to be a main dish but also make an impressive side for any protein.

Nov 5, 2024 - 13:30

The Incredible Casserole Recipe You'll Want To Try ASAP

Tennessee Onions in a dish from above with a large spoon — Simply Recipes / Photo by Morgan Hunt Glaze / Food Styling by Jennifer Wendorf / Prop Styling by Priscilla Montiel

These tender, sweet onions with layers of butter and cheese melting throughout are proof that even the simplest ingredients deserve their time to shine. This homestyle casserole spotlights Vidalia onions, which are only grown in and around Vidalia, Georgia. Their sweetness is credited to the unique soil of the 20-county growing region that surrounds it.

Cooking the onions for a long time enhances their sweetness, perfectly contrasting the salty, melty cheese situation. Even the butter in the bottom of the baking dish is nicely spiced and seasoned. The “sauce” at the bottom of the pan is essentially buttery onion goodness, perfect for dunking.

How To Serve Tennessee Onions

This simple is tasty enough to be the main star of your dinner or an impressive side dish. Serve them as a side dish to just about any protein, like roasted chicken or pan-seared steak. Serve them on top of mashed or baked potatoes, or even just over plain white rice and a simple protein. Is there anything better than buttered rice? You can even pile them on top of a burger or sandwich.

Easy Tweaks to This Recipe

Add dried herbs and different spices like cumin or chili powder to the onions.
Add smashed whole garlic cloves.
Add a few sprigs of hearty herbs like rosemary or thyme.
Swap the cheeses out with others like Muenster, fontina, and Monterey Jack cheese.

Tennessee Onions (Casserole) from above in a casserole dish with a spoon — Simply Recipes / Photo by Morgan Hunt Glaze / Food Styling by Jennifer Wendorf / Prop Styling by Priscilla Montiel

Preheat the oven to 350°F.

Prepare the onions:

Place the onions in a large bowl. Sprinkle with the salt, mustard, garlic powder, and paprika; toss gently to coat. Arrange the onions evenly in a 9x13-inch baking dish.

Top the onions with the butter and cheese and bake:

Arrange the butter pieces evenly over the onions and sprinkle with 1 1/2 cups of the havarti and 1 1/2 cups of the cheddar cheese. Cover with aluminum foil and bake until the onions are soft and the sides of the baking dish are bubbling, about 40 minutes.

Top with the remaining cheese and continue to bake:

Remove the foil and top with the remaining 1/2 cup havarti and 1/2 cup cheddar cheese. Bake until the top is golden, about 30 minutes.

If you’d like the top more browned, increase the oven temperature to broil on high during the last 5 minutes of cooking. Sprinkle with parsley, if desired, and black pepper and serve.

Tennessee onions are best served fresh, but leftovers will keep in an airtight container in the fridge for up to 5 days.

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