Tennessee Onions

I’ve been an onion girl pretty much my whole life. Things locked into place when my mom went through a whole-baked onion phase at some point in my childhood (definitely pre-Bat Mitzvah, but the timing is a bit murky). Whether they’re frizzly-fried, made into onion rings, caramelized in French onion soup, served raw on salads or as pickled onions on my sandwiches, I love them all. As far as I’m concerned, most (savory) dishes can be made better with some onions. So when I heard there was a casserole made of mostly onions, my ears perked all the way up. Then I saw someone scoop some of that onion casserole onto a burger, and I was sold.

While they’re called “Tennessee onions,” the origins are unclear — likely in the Appalachian region, but not necessarily from Tennessee. One thing is for certain: The sweet Vidalia onions that are used to make up the bulk of the recipe actually come from Georgia (go figure!). Regardless, with layers of spiced sweet onions, gooey cheddar, smoked Gouda, and a sprinkling of Parmesan, there is a lot to love in this Southern casserole.

• It’s extra-cheesy! Layers of gooey mild cheddar, smoked Gouda, and a little Parmesan sprinkled on top make this a seriously delicious casserole.
• Easy assembly. This casserole is all about the sweet Vidalia onions and comes together quickly with minimal chopping.

• Onions: Because they’re the star ingredient, it’s worth seeking out uniquely sweet and mild Vidalia onions, but any sweet onion will also work.
• Spices: A combination of mustard powder, garlic powder, smoked paprika, and a little cayenne give this dish a deeply savory, well-rounded flavor.
• Cheese: A combination of gooey mild cheddar and smoked Gouda or cheddar give the casserole a rich texture. A sprinkle of grated Parmesan cheese on top adds an extra boost of cheesy umami.

1. Prep the onions. Separate sliced Vidalia onions into rings and place in a large bowl. Add kosher salt, dry mustard powder, garlic powder, smoked paprika, and cayenne pepper, and toss to coat.
2. Assemble the casserole. Arrange half of the seasoned onion rings in an even layer in a greased baking dish. Sprinkle evenly with half each of the shredded mild cheddar cheese and smoked Gouda cheese. Arrange the remaining onions on top and sprinkle with the remaining mild cheddar and smoked Gouda. Sprinkle evenly with grated Parmesan cheese. Scatter diced unsalted butter on top.
3. Bake the onions. Cover the baking dish with aluminum foil. Bake until the onions are softened and the casserole is bubbling. Uncover and bake until the cheese on top is melted and browned in spots. Sprinkle with chopped fresh parsley leaves if desired.