Creamy Make-Ahead Mashed Potato Casserole with Gruyère Crust
A rich and comforting mashed potato casserole topped with a nutty Gruyère cheese crust, perfect for holidays and make-ahead meals.
- Prep Time: 20 minutes
- Cook Time: 25-30 minutes
- Total Time: 45-50 minutes
- Yield: 8 servings 1x
- Category: Side Dish
- Cuisine: American
Ingredients
Scale
- 4 cups (900g) creamy mashed potatoes, homemade or store-bought
- 1 ½ cups (150g) shredded Gruyère cheese
- 4 tablespoons (60g) unsalted butter, softened
- ½ cup (120ml) heavy cream
- ½ cup (120g) sour cream
- 2 cloves garlic, minced (optional)
- 2 tablespoons green onions or chives, finely chopped
- Salt and pepper to taste
- 1 teaspoon onion powder
- ½ teaspoon paprika
Instructions
- Preheat the oven to 375°F (190°C).
- If starting from scratch, boil 2 pounds (900g) peeled Yukon Gold potatoes until fork-tender, about 15-20 minutes. Drain well.
- Mash the potatoes using a hand mixer or potato masher until smooth but not overmixed.
- Add butter, heavy cream, and sour cream to the mashed potatoes and mix until creamy and well combined.
- Stir in minced garlic, chopped green onions, onion powder, paprika, salt, and pepper. Adjust seasoning to taste.
- Spread the mashed potato mixture evenly in a 9×13-inch casserole dish, smoothing the top with a spatula.
- Generously sprinkle shredded Gruyère cheese over the top to cover the surface completely.
- Bake for 25-30 minutes until the cheese is melted, bubbling, and golden brown with slightly crispy edges.
- Let the casserole rest for 5-10 minutes before serving to allow it to set.
Notes
Use room temperature butter, cream, and sour cream for smoother mixing. Avoid overmixing potatoes to prevent gummy texture. Pre-shred Gruyère for an even golden crust. Let casserole rest before serving for better slicing. Watch oven carefully to avoid burnt cheese. For make-ahead, cover casserole with foil and refrigerate up to 24 hours; bake covered 30 minutes then uncovered 20 minutes to crisp crust. Reheat leftovers in oven at 350°F to maintain crust; avoid microwaving.
Nutrition
- Serving Size: About ½ cup
- Calories: 275
- Sugar: 2
- Sodium: 350
- Fat: 15
- Saturated Fat: 9
- Carbohydrates: 25
- Fiber: 2
- Protein: 8
Keywords: mashed potato casserole, Gruyère crust, make-ahead casserole, holiday side dish, creamy potatoes, comfort food