Garlic-Parmesan Melting Sweet Potatoes

Position rack in upper third of oven; preheat to 450°F. Cut 2 unpeeled sweet potatoes crosswise into 1-inch-thick rounds; transfer to a large bowl.

Add 2 tablespoons melted butter, 2 tablespoons oil, 1 tablespoon herbs, ½ teaspoon salt and ½ teaspoon pepper; toss to coat. Arrange the sweet potatoes in a single layer in a 9-by-13-inch metal baking pan. (Don’t use a glass dish, which could shatter.) Roast, flipping once, until browned, about 35 minutes.

Whisk chopped garlic into 1 cup broth; carefully add the broth mixture to the pan. Sprinkle the tops of the sweet potatoes with 3 tablespoons Parmesan. Continue roasting until the broth has mostly been absorbed and the sweet potatoes are very tender, 12 to 15 minutes more. Transfer to a serving platter; drizzle with the remaining butter mixture from the pan. Sprinkle with more Parmesan, if desired.