Savory Sweet Potato Gratin
A comforting and delicious layered sweet potato gratin that combines the flavors of brown butter, cheese, and fresh herbs, perfect for weeknights or festive dinners.
Ingredients
Sweet Potatoes
- 3 pounds sweet potatoes, peeled and thinly sliced (use a mandoline for uniform slices)
Dairy
- 2 tablespoons unsalted butter (plus extra for the dish; brown the butter for nuttier flavor)
- 1.5 cups heavy cream (use whole milk or half-and-half for a lighter version)
- 1/2 cup sour cream (or use Greek yogurt instead for a tangy, lighter option)
- 1.5 cups grated Gruyere or sharp cheddar (mix for both creaminess and tang)
Vegetables & Seasonings
- 1 medium onion, thinly sliced (optional; caramelized onions add depth)
- 3 cloves garlic, minced (or garlic powder in a pinch)
- 1 teaspoon fresh thyme leaves (plus extra for garnish; rosemary works too)
- 1/2 teaspoon nutmeg (optional—warm, subtle depth)
- to taste Salt and black pepper
Crunchy Topping
- 1/4 cup panko breadcrumbs (optional for a crunchy top; use gluten-free panko if needed)
Sweetener
- a splash maple syrup or honey (optional—brings out the sweet potato’s natural sugars)
Instructions
Preparation
- Preheat the oven to 375°F (190°C). Butter a 9x13 baking dish and set aside.
- In a small saucepan, melt 2 tablespoons butter over medium heat until it foams and the solids turn golden and nutty. Remove from heat and stir in minced garlic and thyme.
- Whisk together heavy cream, sour cream, nutmeg, salt, and pepper in a bowl. Stir in half the grated cheese. Add the brown butter and garlic mixture and a tablespoon of maple syrup if using.
- Arrange a single layer of sweet potato slices in the dish, slightly overlapping. Spoon some cream mixture over the layer so every slice gets a coating. Sprinkle a little cheese and season lightly. Repeat until all slices are layered and the cream mixture is used.
- If you like a crunchy finish, mix panko with a teaspoon of melted butter and sprinkle over the top.
Cooking
- Cover loosely with foil and bake for 30 minutes. Remove foil and bake another 15–25 minutes until the top is golden, bubbling, and the potatoes are tender when pierced with a knife.
- Let the gratin sit for 10 minutes before serving.
Notes
For a dairy-free version, swap cream for canned coconut milk and use vegan cheese. For a savory punch, fold in cooked chopped bacon or smoked tofu. This dish pairs nicely with roasted chicken, glazed ham, or a crisp green salad.