Introduction

Rich Potato Gratin is a comforting, creamy dish perfect for any occasion. Layers of thinly sliced potatoes are baked in a luscious cheese sauce topped with melted gruyere for a golden, flavorful crust. This recipe offers a balance of simple ingredients elevated by aromatic flavors and a silky béchamel sauce.

The image shows a white rectangular baking dish filled with golden baked scalloped potatoes arranged in overlapping, consistent layers. The top layer is made of potato slices covered with melted, bubbly cheese that is browned and crispy in spots, showing a rich, textured surface with golden and light brown colors. The creamy sauce surrounding the potatoes is thick and smooth, with a light off-white tone accented by specks of black pepper and small green thyme sprigs scattered evenly on top. The dish rests on a white marbled surface with a bit of a dark blue cloth visible in the background. photo taken with an iphone --ar 4:5 --v 7

Ingredients

3 tbsp all-purpose or gluten-free flour

1 1/2 cups milk (or heavy cream for extra richness)

1/2 cup shredded gruyere cheese, freshly grated

1 pinch ground nutmeg (optional)

1 tsp fresh thyme, chopped (or 1/2 tsp dried)

3 tbsp butter

1 small onion, minced (about 1/4-inch pieces)

1 garlic clove, grated or freshly minced

Salt and black pepper, to taste

1 cup shredded gruyere cheese, freshly grated

4 lb potatoes, sliced thin (about 1/8-inch thickness)

Instructions

Step 1: Preheat your oven to 350°F. Slice the potatoes into thin 1/8-inch rounds using a mandoline or slicing blade for even cooking. Mince the onion, grate the garlic, chop the thyme, and grate the gruyere cheese. Have all ingredients ready before you start the sauce.

Step 2: Melt butter in a saucepan over medium heat. Add the minced onion, grated garlic, and thyme, sautéing gently for 3-5 minutes until the onion softens and turns translucent without browning to build flavor.

Step 3: Sprinkle the flour over the aromatics and cook, stirring constantly, for 1 minute to form a roux. Slowly whisk in the milk, continuing to whisk until the sauce thickens and coats the back of a spoon. Remove from heat and stir in the 1/2 cup gruyere, nutmeg, salt, and pepper until the cheese melts and the sauce is smooth.

Step 4: Butter a baking dish and pour a thin layer of the cream sauce on the bottom. Arrange half the potato slices in an overlapping pattern over the sauce, then pour half of the remaining sauce over them. Repeat with the remaining potatoes and sauce, filling in gaps to ensure even cooking.

Step 5: Sprinkle the final 1 cup of shredded gruyere evenly over the top. Bake for 45–60 minutes until the potatoes are tender and the top is lightly golden. For a more caramelized crust, broil for 2–3 minutes at the end, watching carefully. Let rest for 10 minutes before serving to set the layers.

Tips & Variations

Use a mandoline slicer to ensure uniform potato slices for even cooking.

Substitute heavy cream for milk to make the gratin richer and creamier.

Add a pinch of cayenne pepper or smoked paprika to the sauce for a subtle kick.

Try mixing in finely chopped fresh herbs like rosemary or sage for added aroma.

For a gluten-free version, use gluten-free flour in the béchamel sauce.

FAQs

Can I use other types of cheese instead of gruyere?

Yes, cheeses like cheddar, fontina, or comté work well as substitutes, though they will alter the flavor profile slightly. Choose cheeses that melt smoothly for the best texture.

Do the potatoes need to be pre-cooked before baking?

No need to pre-cook. Thin, uniform slices allow the potatoes to cook fully in the creamy sauce during the baking time. Using a mandoline helps achieve the ideal thickness.