Description

This Crispy Parmesan and Gruyere Potato Gratin is a luscious, cheesy dish perfect as a comforting side. Thinly sliced Yukon Gold or Russet potatoes are layered and baked in a creamy sauce made with butter, garlic, cream, milk, and thyme, then topped with a golden, crispy crust of Gruyere, Parmesan cheese, and optional breadcrumbs for extra crunch. This rich and flavorful gratin is ideal for family dinners or special occasions.

Ingredients

Scale

Potatoes

3 lbs Yukon Gold or Russet potatoes, peeled and thinly sliced

Creamy Sauce

1 cup heavy cream
1 1/2 cups whole milk
2 tablespoons unsalted butter
2 garlic cloves, minced
1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried thyme)
1/2 teaspoon salt
1/4 teaspoon black pepper

Cheese and Topping

1 cup grated Gruyere cheese
1 cup grated Parmesan cheese
1/2 cup breadcrumbs (optional, for extra crispy topping)
1 tablespoon fresh parsley (optional, for garnish)

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Instructions

Preheat the Oven: Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish with butter or cooking spray to prevent sticking.
Prepare the Potato Layers: Peel the potatoes and slice them thinly, about 1/8-inch thick, using either a sharp knife or a mandolin slicer for uniform pieces. Set the slices aside.
Make the Creamy Sauce: In a saucepan over medium heat, melt the butter. Add the minced garlic and thyme, and cook for about 1 minute until fragrant but not browned. Pour in the heavy cream and whole milk, stirring to combine. Season the mixture with salt and black pepper. Bring it to a gentle simmer and cook for 2-3 minutes, then remove from heat.
Layer the Potatoes: Arrange a layer of the thin potato slices at the bottom of your prepared baking dish, overlapping them slightly for even coverage. Continue layering until all the potato slices are used.
Add the Cheese and Cream: Pour the warm creamy sauce evenly over the layered potatoes, making sure it seeps into the layers. Sprinkle the grated Gruyere cheese and Parmesan cheese evenly on top. If using, sprinkle the breadcrumbs over the cheese for an extra crispy crust.
Bake the Gratin: Cover the baking dish with aluminum foil and bake in the preheated oven for 45 minutes. Then remove the foil and bake for another 15-20 minutes until the top is golden brown and crisp, and the potatoes are tender when pierced with a fork.
Serve: Allow the gratin to rest for about 10 minutes before serving. Garnish with freshly chopped parsley if desired for a fresh, colorful touch.

Notes

Using a mandoline slicer ensures uniform potato slices for even cooking.
You can substitute Gruyere with other melting cheeses like Emmental or Fontina if unavailable.
For gluten-free option, omit breadcrumbs or use gluten-free breadcrumbs.
Make ahead tip: Assemble the gratin a few hours before baking and keep refrigerated, then bake just before serving.
Letting the dish rest after baking allows the sauce to thicken and potatoes to set for easier serving.

Prep Time: 20 minutes
Cook Time: 1 hour 15 minutes
Category: Side Dish
Method: Baking
Cuisine: French