The Cheapest Thanksgiving Side Dish You Can Make This Year

I’m not one to shy away from onions in my cooking. From creamy onion soup to hamburger steaks topped with onions and gravy, they’re a staple in my kitchen—I love the extra flavor they bring to nearly any recipe. As a kid, I avoided onions in all forms, but as an adult food writer, I’ve completely changed my tune and now embrace the crunchy vegetable for the depth it adds to dishes.

When Tennessee Onions started showing up in my TikTok feed, even this onion convert was skeptical. Millions of TikTokers were sharing their versions of the dish—made with sweet Vidalia onions and lots of butter—but could a casserole dish full of cheesy, baked onions really be that good? When one creator called it one of her favorite side dishes, I decided to give it a try in my own kitchen.

What Are Tennessee Onions?

Tennessee Onions have many layers—literally. The dish features sliced sweet onions, shredded cheese, butter, and spices baked together in a 9×13-inch casserole dish until the onions are soft and flavorful. While TikTok offers endless variations, one rule is universal: use a sweet onion, preferably Vidalia.

Chelsea Page, interim executive director at the Vidalia Onion Committee, says Vidalia onions are perfect for the recipe because of their “unique flavor and sweetness.”

How To Make Tennessee Onions

To make this viral side, I started with a 3-pound bag of Vidalia onions, peeling and slicing most of them into 1/4-inch-thick rings. I greased my 9×13-inch baking dish and filled it to the brim with sweet onions and topped them with thin pats of butter—one full stick. The butter is vital in any Tennessee Onions recipe, as it melts over the raw onions and helps them cook down and soften in the oven.

After watching many TikTok videos with different creators sharing their take on the dish, I chose my next steps based on the flavor profiles that sounded best to me. That’s the beauty of Tennessee Onions—there’s room to experiment with the spices and types of cheese you most enjoy. I used garlic salt, freshly ground black pepper, parsley, and paprika, but you could tweak the recipe to use any spice combination that sounds good to you. Next, I sprinkled about 1 cup each of shredded Cheddar and mozzarella cheese on top, then finished it with about a half cup of shredded Parmesan cheese.

I compared many varying cook times and oven temperatures for baking my Tennessee Onions and assumed the longer my casserole dish baked, the softer and more delicious the onions would become. I was right. The sweet spot for my Vidalia onion casserole was baking it covered with foil for 40 minutes at 350 degrees F (176 degrees C). I then raised the heat to 425 degrees F (218 degrees C) and baked the Tennessee Onions uncovered for another 30 minutes until the onions were soft and the cheese was lightly browned on top.

What Do Tennessee Onions Taste Like?

The finished dish tasted like French onion soup in casserole form. The Vidalia onions turned sweet and tender in the oven, and the cheeses melted perfectly, with a few caramelized bits that provided extra flavor. Savory spices like garlic salt and black pepper perfectly complemented the onion’s sweetness, and the melty butter throughout the dish provided a rich, decadent backdrop to the casserole.

What To Serve with Tennessee Onions

I served my Tennessee Onions with country-fried cube steak and white gravy, and I tossed some frozen potato wedges in the air fryer. The meal felt distinctly Southern and pleased everyone at my dinner table—especially my husband, who created his take on loaded potato wedges by topping the air-fried spuds with gravy, steak, and a heaping pile of Tennessee Onions.

The casserole was buttery and cheesy, and the soft, butter-braised texture of the sweet Vidalia onions would be the perfect accompaniment to a holiday dinner—be it Thanksgiving turkey or Christmas ham. What’s more, since onions are the main ingredient, it’s an economical side to add to your holiday menu.

Like many TikTok trends, creators who are sharing their love of Tennessee Onions did not steer me in the wrong direction. The toasty, oniony dish will remain in my side dish rotation. Since the friends and family I asked about the dish had never heard of it, I’m looking forward to making the tasty side for Thanksgiving and teaching the people I love about my new favorite way to eat onions.