Description
This delicious Scalloped Sweet Potatoes recipe, also known as Sweet Potatoes Au Gratin, features layers of tender sweet potatoes baked in a creamy mixture of heavy cream, milk, sautéed onions, garlic, and aromatic thyme. Topped with a blend of sharp cheddar and Parmesan cheeses along with a crispy breadcrumb crust, this comforting casserole is perfect as a hearty side dish for any meal.
Ingredients
Scale
Vegetables
- 4 large sweet potatoes, peeled and thinly sliced
- 1 medium onion, thinly sliced
- 3 cloves garlic, minced
- 2 tablespoons fresh thyme, chopped (or 1 tablespoon dried thyme)
Dairy
- 2 cups heavy cream
- 1 cup milk
- 2 cups shredded sharp cheddar cheese
- 1 cup grated Parmesan cheese
- 2 tablespoons butter
Other
- Salt and pepper, to taste
- 1/2 teaspoon nutmeg (optional)
- 1 cup bread crumbs (for topping)
- Olive oil or melted butter for drizzling (optional)
Instructions
- Preheat Oven: Preheat your oven to 350°F (180°C) to prepare for baking the dish evenly.
- Parboil Sweet Potatoes: In a large pot, bring water to a boil. Add the thinly sliced sweet potatoes and cook for about 5 minutes until slightly tender. Drain and set aside to prevent overcooking during baking.
- Sauté Onions: In a saucepan over medium heat, melt the butter. Add the sliced onion and sauté for 3-4 minutes until translucent and fragrant, creating a flavorful base.
- Add Garlic and Dairy: Stir in the minced garlic and cook for an additional minute. Then add the heavy cream and milk, stirring to combine thoroughly.
- Season Cream Mixture: Season the cream mixture with fresh thyme, salt, pepper, and nutmeg if using. Bring it to a gentle simmer and then remove from heat to preserve the delicate flavors.
- Layer Ingredients: Grease a baking dish and create the first layer by spreading half of the sweet potato slices evenly. Pour half of the onion-cream mixture on top, then sprinkle with half of the cheddar and Parmesan cheeses.
- Add Second Layer: Repeat layering with the remaining sweet potatoes, cream mixture, and cheeses, ensuring even coverage.
- Top with Breadcrumbs: Sprinkle the top with bread crumbs for a crunchy crust. Optionally, drizzle with olive oil or melted butter to enhance browning.
- Bake Covered: Cover the baking dish with aluminum foil and bake in the preheated oven for 45 minutes to allow the potatoes to cook through and flavors to meld.
- Bake Uncovered: Remove the foil and continue baking for an additional 15-20 minutes until the cheese topping is bubbly, golden brown, and crisp.
- Rest and Serve: Let the scalloped sweet potatoes cool for a few minutes before serving so the casserole sets properly for neat slices and optimal flavor.
Notes
- Parboiling the sweet potatoes ensures they cook fully and evenly in the oven without becoming mushy.
- For a lighter version, substitute half-and-half or whole milk for the heavy cream, but the dish will be less rich.
- Fresh thyme offers the best flavor but dried thyme is a convenient substitute.
- Adding a pinch of nutmeg enhances the warmth and complexity of the creamy sauce but can be omitted if preferred.
- If gluten-free breadcrumbs are needed, substitute regular breadcrumbs accordingly.
- This dish can be prepared a day ahead, stored covered in the fridge, and baked before serving.
