Potato Leek Gruyere and Oyster Mushroom Gratin

Elevate your comfort food game with this luxurious Potato Leek Gruyere and Oyster Mushroom Gratin, a decadent dish that combines rich, savory flavors and velvety textures. Layers of tender, thinly sliced russet potatoes, sautéed leeks, and earthy oyster mushrooms are brought together with a luscious cream sauce infused with garlic, thyme, and a hint of nutmeg. The crown jewel? A blanket of nutty Gruyere cheese that melts into golden, bubbly perfection. With just the right balance of creaminess and umami, this gratin is a show-stopping side dish or a hearty vegetarian main that's ideal for holidays or cozy gatherings. Serve it piping hot, straight from the oven, and watch it become the star of your table.

Nutriscore Rating: 66/100

Prep Time:25 mins

Cook Time:45 mins

Total Time:70 mins

Servings: 6

Ingredients

• 4 large Russet potatoes
• 2 large Leeks
• 8 ounces Oyster mushrooms
• 2 cups (shredded) Gruyere cheese
• 1.5 cups Heavy cream
• 2 tablespoons Unsalted butter
• 2 cloves (minced) Garlic
• 1 teaspoon Fresh thyme
• 2 tablespoons Olive oil
• 1.5 teaspoons Salt
• 1 teaspoon Black pepper
• 0.25 teaspoons (optional) Nutmeg

Directions

Step 1

Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with butter or olive oil and set it aside.

Step 2

Peel the potatoes and slice them into thin, 1/8-inch rounds using a mandoline slicer or sharp knife. Place the slices in a bowl of cold water to prevent browning.

Step 3

Trim and clean the leeks, discarding the tough green tops. Slice the leeks into thin rounds and rinse thoroughly to remove any dirt.

Step 4

In a large skillet, heat olive oil over medium heat. Add the sliced leeks and sauté for 4-5 minutes until softened. Add the minced garlic and thyme, cooking for an additional minute. Transfer the mixture to a bowl.

Step 5

Using the same skillet, melt the butter and add the oyster mushrooms. Sauté for 5-7 minutes until they release their liquid and are lightly browned. Remove from heat and combine with the leek mixture.

Step 6

In a small saucepan, heat the heavy cream gently over low heat. Stir in the salt, black pepper, and nutmeg (if using). Do not let the cream boil; just warm it through.

Step 7

Drain the potatoes and pat them dry with paper towels. Begin layering the gratin: Arrange a single layer of potato slices in the bottom of the prepared baking dish, slightly overlapping each piece.

Step 8

Spread a portion of the leek and mushroom mixture over the potatoes, followed by a sprinkle of shredded Gruyere cheese. Repeat the layering process until all the ingredients are used, finishing with a layer of Gruyere on top.

Step 9

Pour the warm cream evenly over the layered gratin, ensuring it seeps through to the bottom.

Step 10

Cover the baking dish with aluminum foil and bake for 30 minutes in the preheated oven.

Step 11

After 30 minutes, remove the foil and bake for an additional 15 minutes, or until the top is golden and bubbly and the potatoes are fork-tender.

Step 12

Allow the gratin to rest for 10 minutes before serving. Garnish with fresh thyme if desired.

Nutrition Facts

Serving size	(2404.6g)

Amount per serving	% Daily Value*
Calories	4113.3

Total Fat 252.5g	0%
Saturated Fat 136.9g	0%
Polyunsaturated Fat 2.7g
Cholesterol 691.6mg	0%
Sodium 4751.1mg	0%
Total Carbohydrate 324.3g	0%
Dietary Fiber 32.3g	0%
Total Sugars 30.3g
Protein 121.4g	0%

Vitamin D 0IU	0%
Calcium 2898.5mg	0%
Iron 23.4mg	0%
Potassium 8343.6mg	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: 56.0%

Protein: 12.0%

Carbs: 32.0%