Description
A creamy, cheesy Sweet Potato Gratin featuring thinly sliced sweet potatoes layered with melted butter, fresh thyme, and a blend of Gruyere and Parmesan cheeses, baked to golden perfection. This comforting side dish combines the natural sweetness of sweet potatoes with rich, savory flavors, perfect for holiday dinners or cozy family meals.
Ingredients
Sweet Potatoes
- 5 medium sweet potatoes – about 2 lbs
Cheese and Herbs
- 1 cup grated Gruyere cheese
- 2/3 cup grated Parmesan cheese
- 1.5 tablespoons fresh thyme – plus more for serving
Seasonings and Butter
- 2 tablespoons butter – melted
- 1 teaspoon kosher salt
- 1/2 teaspoon ground black pepper
- 1/2 teaspoon garlic powder
Instructions
- Preheat and prepare dish: Preheat your oven to 425 °F. Lightly grease a 3-quart gratin dish or a 9×13-inch baking dish with butter or oil to prevent sticking.
- Prepare sweet potatoes: Thoroughly wash and dry the sweet potatoes. Peel them using a vegetable peeler, discarding the peels. Using a mandolin slicer, slice the sweet potatoes into thin slices about 1/8 inch thick for even cooking.
- Toss potatoes with seasonings: Place the sliced sweet potatoes into a large mixing bowl. Add melted butter, fresh thyme, kosher salt, black pepper, and garlic powder. Toss everything well to evenly coat the potatoes with the butter and seasonings.
- Layer the gratin: Arrange one-third of the seasoned sweet potato slices in an even layer in the bottom of the prepared baking dish, overlapping them slightly. Sprinkle one-third of the mixed Gruyere and Parmesan cheese evenly over the potatoes. Press the potatoes down gently to fit snugly. Repeat the layering process two more times, finishing with the remaining cheese on top.
- Bake: Place the gratin in the preheated oven and bake until the sweet potatoes are tender when pierced with a fork and the cheese on top is golden brown and bubbling, about 45 to 50 minutes.
- Serve: Remove from the oven and let cool for a few minutes. Garnish with extra fresh thyme leaves before serving to add a fresh herbal aroma.
Notes
- Use a mandolin slicer to ensure uniformly thin sweet potato slices for even baking.
- You can substitute Gruyere with a similar melting cheese like Swiss if needed.
- Fresh thyme adds brightness, but dried thyme can be used in a pinch.
- If you prefer a creamier gratin, consider adding a splash of cream or milk between layers.
- Ensure the baking dish is well greased to prevent sticking and ease serving.
