Savory Sweet Potato Gratin

A warm, creamy gratin featuring layers of sweet potatoes, onions, and cheese, perfect for festive occasions or comforting weeknight meals.

Prep Time 20

Cook Time 55

Total Time 1 15

Course Side Dish, Vegetarian

Cuisine American

Servings 6 servings

Calories 450 kcal

3 pounds sweet potatoes, peeled and thinly sliced About 4 medium; use a mandoline for uniform slices.
2 tablespoons unsalted butter Substitute olive oil for a dairy-free option.
1 medium yellow onion, thinly sliced Shallots can be used as an alternative.
3 cloves garlic, minced Aromas will fill your kitchen as it cooks.
1.5 cups heavy cream Use half-and-half for a lighter version or full-fat coconut milk for dairy-free.
1 cup grated Gruyere or sharp cheddar Melts beautifully; goat cheese can be substituted.
0.5 cup grated Parmesan Adds savory umami and a crisp top.
1 teaspoon fresh thyme leaves Or substitute with 1/2 teaspoon dried thyme.
to taste Salt and freshly ground black pepper
a pinch nutmeg Optional; adds warmth that pairs well with sweet potatoes.
0.5 cup panko or crushed pecans for topping Panko provides crunch, pecans add sweetness.
4 slices cooked bacon, chopped Optional for smoky flavor; omit for vegetarian.

Preheat the oven to 375°F (190°C). Butter a 9x13-inch baking dish and set aside.
In a skillet over medium heat, melt butter and sauté the onion until translucent and slightly caramelized, about 8 minutes.
Add garlic and thyme, cook for 1 more minute until fragrant.

In a bowl, whisk together heavy cream, 1/2 cup Gruyere, Parmesan, nutmeg, salt, and pepper.
Layer one-third of the sweet potato slices in the baking dish, overlapping like shingles.
Spoon one-third of the sautéed onion mixture over the potatoes, then drizzle one-third of the cream mixture and sprinkle a bit of cheese.
Repeat two more times until all potatoes and cream are used; add chopped bacon if using.
Finish with remaining cheese and top with panko or pecans. Dot with small bits of butter if desired.

Cover the dish tightly with foil and bake for 35 minutes.
Remove the foil and bake for another 20 minutes until the top is golden and a knife slides through easily.
Let rest for 10 minutes to help the gratin set before serving.

For a sweet-savory contrast, add thinly sliced apples. For a vegan version, substitute with coconut milk and cashew cheese.

Keyword Comfort Food, Festive Cooking, holiday recipe, Sweet Potato Gratin, Vegetable Side Dish