— Kelsey Nixon
2 Tbsp. unsalted butter
1 large yellow onion, finely chopped
2 garlic cloves, minced
1 1/4 cups heavy cream
1/4 cup low-sodium chicken broth
2 tsp. chopped fresh thyme leaves
1 1/2 tsp. kosher salt
1/2 tsp. cracked black pepper
2 lb. sweet potatoes, peeled and cut into 1/8-inch-thick slices
2 oz. (about 1/2 cup) Gruyère cheese, shredded
Preheat the oven to 375 degrees.
In a cast-iron skillet set over medium-high heat, melt the butter. Add the onion and cook, stirring, until softened and beginning to brown, about 5 minutes. Add the garlic and cook for 1 minute. Stir in the cream, broth, and thyme, and season with the salt and pepper. Add half of the sweet potato slices in a flat layer, then half of the cheese, then the remaining sweet potatoes. Bring to a simmer; do not stir. Reduce the heat to medium-low and cook for 5 minutes longer. Top with the remaining cheese and transfer the skillet to the oven.
Bake until bubbling and the surface begins to brown, about 15 minutes. Let cool for 10 minutes before serving. Serves 6.
— From "Kitchen Confidence: Essential Recipes and Tips That Will Help You Cook Anything" by Kelsey Nixon (Clarkson Potter, $19.99)