Pumpkin-Potato Gratin

Place potatoes into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until tender, about 15 minutes.

Meanwhile, combine pumpkin, vegetable broth, white wine, and rosemary in a saucepan over medium heat. Bring to a boil; reduce heat, cover, and simmer for 15 minutes. Add onion and simmer for 10 minutes more. Remove rosemary sprig and season with salt and pepper.

Preheat the oven to 350 degrees F (175 degrees C).

Cut potatoes into thick slices and place 1/2 of the potatoes in a baking dish. Cover with 1/2 of the tomato slices and 1 teaspoon oregano leaves. Season with salt and pepper. Cover with 1/2 of the Cheddar cheese.

Pour pumpkin and cooking liquid on top. Cover with remaining potatoes and tomatoes. Sprinkle with remaining oregano. Mix remaining Cheddar cheese and bread crumbs together and evenly sprinkle over the top.

Bake in the preheated oven until cooked through and lightly browned on top, 25 to 40 minutes.