Savory Sweet Potato Gratin

A comforting and elegant dish of layered sweet potatoes baked in creamy garlic and herb-infused sauce, perfect for weeknight dinners or festive gatherings.

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Prep Time 20

Cook Time 1

Total Time 1 20

Servings: 8 servings

Course: Side Dish, Vegetarian

Cuisine: American, Comfort Food

Calories: 350

Ingredients Method Notes

Ingredients

Sweet Potato Layer

3 pounds sweet potatoes, peeled and thinly sliced Choose firm, orange-fleshed sweet potatoes for sweetness and color.

Cream Mixture

2 cups heavy cream Can use half-and-half or evaporated milk for a lighter option.
3 cloves garlic, minced Or 1 teaspoon garlic powder in a pinch.
1 tablespoon fresh rosemary, finely chopped Thyme or sage work beautifully as substitutes.
1 cup Gruyere or sharp cheddar, grated For vegetarian options, try smoked provolone or omit for dairy-free.
1/2 cup Parmesan, grated Adds a salty, nutty top.
2 tablespoons unsalted butter, melted Can substitute with olive oil for dairy-free.
1 pinch nutmeg Optional, for warmth.
1 tablespoon flour Can use cornstarch for gluten-free thickening.
to taste salt and freshly ground black pepper

Optional Add-Ins

optional bacon or pancetta Add between layers for smoky depth.
optional chopped parsley and lemon zest Add after baking for brightness.
optional thinly sliced apples or pears Layer in for a sweet-salty contrast.

Method

Preparation

Preheat oven to 375°F (190°C). Butter a 9x13-inch baking dish or ovenproof skillet.
In a saucepan over low heat, warm heavy cream with minced garlic, rosemary, a pinch of nutmeg, salt, and pepper.
Whisk in flour until slightly thickened, then remove from heat.

Layering

Arrange a single overlapping layer of sweet potato slices in the dish. Sprinkle with salt, pepper, and a light dusting of Gruyere.
Repeat layering with the remaining slices, reserving some cheese for the top.

Baking

Pour the warm cream mixture evenly over the layered potatoes, pressing down gently so the cream fills the gaps.
Dot the top with melted butter and finish with remaining Parmesan and Gruyere.
Cover the dish tightly with foil and bake for 35 minutes.
Uncover and continue baking for 20-30 minutes until the top is golden and a knife slides easily through the potatoes.
For a crispier crust, broil for 1-2 minutes at the end while watching closely.

Serving

Let the gratin rest for 10 minutes before serving to allow layers to settle.

Notes

Store leftovers for up to 4 days in an airtight container or freeze for up to 3 months. Revive creaminess by adding a splash of cream or butter before reheating.