- 3 pounds mixed russet potatoes and sweet potatoes
- Butter for baking dish and foil
- 1 1/2 cups heavy whipping cream
- 1/2 cup chicken broth
- 1 tablespoon chopped sage
- 1 minced garlic clove
- 1 teaspoon kosher salt
- ground black pepper
- 1 cup grated Gruyère cheese
- Spread potatoes in a buttered 11×7-inch baking dish. Combine heavy whipping cream, chicken broth, chopped sage, garlic, and salt; pour over potatoes. Sprinkle with pepper. Cover with buttered foil; bake at 425°F for 35 minutes. Sprinkle with Gruyère cheese. Bake uncovered until brown and bubbling, about 25 minutes. Let rest before serving.