Potato Gratin with Mushrooms and Gruyre

Indulge in the ultimate comfort food with this Potato Gratin with Mushrooms and Gruyère—a decadent dish that layers velvety russet potatoes, earthy sautéed cremini mushrooms, and nutty Gruyère cheese, all bathed in a rich cream and thyme-infused sauce. Perfectly baked until golden and bubbling, this crowd-pleaser combines creamy textures with a savory depth of flavor that’s irresistible. Optional breadcrumbs add a satisfying crunch to the top, making it a stunning centerpiece for holiday tables or a cozy weeknight dinner. Easy to prepare and full of gourmet flair, this potato gratin is the perfect side dish or main course to elevate any meal.

Nutriscore Rating: 63/100

Prep Time:20 mins

Cook Time:60 mins

Total Time:80 mins

Servings: 6

Ingredients

• 4 large Russet potatoes
• 8 ounces Cremini mushrooms
• 2 cups Gruyère cheese
• 1.5 cups Heavy cream
• 0.5 cups Whole milk
• 2 cloves Garlic
• 2 tablespoons Unsalted butter
• 1 teaspoon Fresh thyme
• 1 teaspoon Salt
• 0.5 teaspoon Black pepper
• 0.25 cup Breadcrumbs (optional for topping)

Directions

Step 1

Preheat your oven to 375°F (190°C) and grease a 9x13-inch baking dish with butter or non-stick spray.

Step 2

Peel the potatoes and slice them thinly (about 1/8-inch thick) using a sharp knife or mandoline. Set the slices aside in a bowl of cold water to prevent browning.

Step 3

Clean and slice the mushrooms. Heat 2 tablespoons of butter in a skillet over medium heat and sauté the mushrooms with a pinch of salt until golden brown and their moisture has evaporated, about 6-8 minutes. Remove from heat and set aside.

Step 4

Grate the Gruyère cheese and set aside.

Step 5

In a medium saucepan, combine the heavy cream, whole milk, minced garlic, thyme, 1 teaspoon of salt, and 1/2 teaspoon of black pepper. Heat over low-medium heat until the mixture is warm and fragrant, but do not let it boil. Remove from heat.

Step 6

Drain the potato slices and pat them dry with a clean kitchen towel.

Step 7

Begin assembling the gratin by layering 1/3 of the potato slices in the prepared baking dish, slightly overlapping them. Sprinkle 1/3 of the sautéed mushrooms and 1/3 of the grated Gruyère on top.

Step 8

Repeat the layering process two more times, finishing with a layer of cheese on top.

Step 9

Pour the warm cream mixture evenly over the layered potatoes. Gently press down with a spatula to ensure all the potatoes are submerged in the liquid.

Step 10

If using, sprinkle breadcrumbs on top for an added crunchy texture.

Step 11

Cover the baking dish with aluminum foil and bake in the preheated oven for 40 minutes. Then, remove the foil and bake uncovered for an additional 20 minutes, or until the top is golden brown and the potatoes are tender when pierced with a knife.

Step 12

Let the gratin rest for 10 minutes before serving to allow it to set. Serve warm and enjoy!

Nutrition Facts

Serving size	(2235.5g)

Amount per serving	% Daily Value*
Calories	3871.0

Total Fat 234.8g	0%
Saturated Fat 138.5g	0%
Polyunsaturated Fat 4.7g
Cholesterol 727.0mg	0%
Sodium 4743.9mg	0%
Total Carbohydrate 295.1g	0%
Dietary Fiber 24.3g	0%
Total Sugars 26.8g
Protein 126.0g	0%

Vitamin D 132.9IU	0%
Calcium 3076.6mg	0%
Iron 16.7mg	0%
Potassium 8210.6mg	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: 55.6%

Protein: 13.3%

Carbs: 31.1%