Sweet and White Potato Gratin

Elevate your side dish game with this indulgent Sweet and White Potato Gratin, a visually stunning and flavor-packed twist on the classic gratin recipe. This dish expertly layers creamy sweet potatoes and tender white potatoes—like Yukon Gold or Russet—with a rich blend of heavy cream, garlic, and fresh thyme for a comforting, herbaceous undertone. Topped with a decadent combination of Gruyère and Parmesan cheeses, this gratin bakes to golden-bubbly perfection, offering both creamy and crispy textures in every bite. Perfect for holidays, dinner parties, or a hearty weeknight side, this gratin pairs wonderfully with roasted meats or a crisp green salad. Simple to prepare yet irresistibly elegant, this recipe is sure to become a household favorite.

Nutriscore Rating: 54/100

Prep Time:20 mins

Cook Time:60 mins

Total Time:80 mins

Servings: 6

Ingredients

• 2 large Sweet potato
• 2 large White potato (e.g., Yukon Gold or Russet)
• 2 tablespoons Unsalted butter
• 2 cloves Garlic
• 2 cups Heavy cream
• 1 cup Whole milk
• 2 teaspoons Fresh thyme (leaves picked)
• 2 teaspoons Salt
• 1 teaspoon Ground black pepper
• 1.5 cups Gruyère cheese (shredded)
• 0.5 cups Parmesan cheese (grated)
• 1 teaspoon Olive oil

Directions

Step 1

Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with 1 teaspoon of olive oil or butter.

Step 2

Wash, peel, and thinly slice sweet potatoes and white potatoes into 1/8-inch slices using a sharp knife or a mandoline slicer. Keep the slices in separate piles for layering.

Step 3

In a medium saucepan over low heat, melt the butter. Add minced garlic and cook for 1-2 minutes until fragrant, but not browned.

Step 4

Pour in the heavy cream and milk. Stir in thyme, salt, and pepper. Heat gently until warm, but do not let the mixture boil. Remove from heat.

Step 5

Spread a thin layer of the cream mixture on the bottom of the prepared baking dish.

Step 6

Make the first layer using half of the sweet potato slices, slightly overlapping them. Sprinkle 1/3 of the Gruyère and a little Parmesan over the top. Pour about 1/3 of the cream mixture over this layer.

Step 7

Next, make a layer with all of the white potato slices, overlapping slightly. Sprinkle another 1/3 of the Gruyère and a little Parmesan. Pour another 1/3 of the cream mixture over this layer.

Step 8

Finish with the remaining sweet potato slices as the top layer. Sprinkle the rest of the Gruyère and Parmesan on top. Pour the remaining cream mixture evenly over the entire dish.

Step 9

Cover the baking dish tightly with aluminum foil and place it in the preheated oven. Bake for 40 minutes.

Step 10

Remove the foil and bake uncovered for an additional 20 minutes, or until the top is golden brown, the cheese is bubbling, and the potatoes are tender when pierced with a fork.

Step 11

Allow the gratin to rest for 10 minutes before serving to let it set. Garnish with a sprinkle of fresh thyme, if desired.

Nutrition Facts

Serving size	(2034.3g)

Amount per serving	% Daily Value*
Calories	4134.9

Total Fat 309.7g	0%
Saturated Fat 174.1g	0%
Polyunsaturated Fat 6.2g
Cholesterol 868.8mg	0%
Sodium 8715.3mg	0%
Total Carbohydrate 184.6g	0%
Dietary Fiber 17.1g	0%
Total Sugars 36.2g
Protein 119.6g	0%

Vitamin D 117.4IU	0%
Calcium 3499.6mg	0%
Iron 6.5mg	0%
Potassium 3621.0mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 69.6%

Protein: 11.9%

Carbs: 18.4%