Cheesy Sweet Potato Au Gratin
This sweet potato au gratin features thinly sliced potatoes baked in a rich and creamy Gruyere cheese sauce with a hint of garlic and thyme. It's a comforting, savory-sweet side dish that’s perfect for any occasion.
Ingredients
- 3 pounds sweet potatoes (peeled and thinly sliced 1/8 inch)
- 1 ½ cups heavy cream
- 1 ½ cups shredded Gruyere cheese (divided)
- ½ cup grated Parmesan cheese
- 4 tablespoons butter (divided)
- 2 cloves garlic (minced)
- 1 teaspoon fresh thyme leaves
- salt and black pepper to taste
Instructions
- Preheat oven: Set your oven to 400°F (200°C). Grease a 9x13 inch baking dish with 1 tbsp of butter.
- Make cream Ssuce: Melt 3 tbsp of butter in a saucepan over medium heat. Cook 2 minced garlic cloves for 1 minute. Stir in 1 ½ cups of heavy cream and simmer gently.
- Add cheese: Remove the pan from the heat. Stir in 1 cup of Gruyere, ½ cup of Parmesan, and 1 tsp of thyme until smooth. Season with salt and pepper.
- Layer potatoes: Arrange half of the sweet potato slices in the prepared dish. Pour half of the creamy sauce over the top.
- Add final layer: Layer the remaining sweet potato slices on top. Pour the rest of the sauce over everything. Sprinkle with the remaining ½ cup of Gruyere.
- Bake and serve: Bake for 45-55 minutes, until the top is golden and the potatoes are tender. Let it rest for 10 minutes before serving. ENJOY!
Notes
- A mandoline slicer is highly recommended for even slices.
- Grating your own cheese will give you the creamiest results.
- Let the gratin rest before serving so the sauce can set.
- Feel free to add a pinch of nutmeg for extra warmth.
- Store any leftovers in the fridge for up to 4 days.