Name: Rich Potato Gratin Recipe
Prep time: 30 min
Cook time: PT-491717H21M48S
Total time: 1 h 15 min
Cuisine: French
Ingredients: 3 tbsp all-purpose flour (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 unsalted butter; 1 small onion, minced (about 1/4-inch pieces); 1 garlic clove, grated; Salt and black pepper, to taste; 1 cup shredded Gruyere cheese (freshly grated); 4 lb potatoes, sliced thin (about 1/8-inch thickness)

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Introduction

Rich Potato Gratin is a classic comfort dish featuring thinly sliced potatoes baked in a creamy, cheesy sauce until golden and bubbling. This recipe combines the nutty flavor of gruyere cheese with aromatic herbs for a decadent side that’s perfect for family dinners or special occasions.

A white rectangular dish filled with a creamy potato gratin, showing thinly sliced potato layers arranged in rows, each golden yellow slice topped with bubbly, browned melted cheese with crisp spots. The creamy sauce around the potatoes is white and smooth, slightly thick, with small specks of black pepper and sprigs of green herbs scattered on top. The edges of the potatoes have a slightly caramelized, crispy texture, contrasting with the soft creamy sauce. The dish rests on a white marbled surface with a deep blue cloth partially visible in the background. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

3 tbsp flour (all-purpose or gluten-free)
1 1/2 cups milk (or heavy cream for extra richness)
1/2 cup shredded gruyere cheese (freshly grated if possible)
1 pinch ground nutmeg (optional but recommended for depth)
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 (freshly minced preferred)
Salt and black pepper, to taste
1 cup shredded gruyere cheese (freshly grated for best melting)
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 helps ensure even cooking. Mince the onion, grate the garlic, chop the thyme, and grate the gruyere cheese. Having these prepared allows you to focus on making the sauce smoothly.
Step 2: Melt the butter over medium heat in a saucepan. Add the minced onion, grated garlic, and thyme. Sauté gently for 3-5 minutes until the onion is soft and translucent, developing a flavorful base without browning.
Step 3: Sprinkle the flour over the aromatics and cook for 1 minute, stirring constantly to form a roux and remove the raw flour taste. Slowly pour in the milk while whisking vigorously to avoid lumps. Continue whisking for 1-2 minutes until the sauce thickens and coats the back of a spoon. Remove from heat and stir in the 1/2 cup gruyere cheese, nutmeg, salt, and pepper until smooth and creamy.
Step 4: Butter a baking dish and pour a thin layer of the cream sauce on the bottom to prevent sticking. Arrange half the potato slices in overlapping layers, then cover with half the remaining sauce. Repeat with the rest of the potatoes and sauce, filling gaps to ensure even cooking.
Step 5: Sprinkle the remaining cup of gruyere cheese evenly over the top. Bake at 350°F for 45-60 minutes until the potatoes are tender and the top is light golden brown. For a deeper crust, broil for 2-3 minutes at the end, watching carefully to prevent burning. Let rest 10 minutes before serving to set the layers and achieve a creamy texture.

Tips & Variations

Use a mandoline to slice potatoes evenly for uniform cooking.
Swap gruyere with Swiss or cheddar cheese if preferred, but keep it shredded for best melting.
Add a sprinkle of breadcrumbs on top before baking for extra crunch.
Mix in cooked bacon or caramelized onions between layers for added flavor.

Storage

Store any leftovers covered in the refrigerator for up to 3 days. Reheat gently in the oven at 350°F until warmed through to preserve the creamy texture. Avoid microwaving as it can make the sauce separate. You can also prepare the gratin the night before and bake just before serving for convenience.

How to Serve

A white rectangular baking dish filled with a creamy layered potato gratin. The dish shows several thin, golden-yellow potato slices arranged in overlapping rows on top, each slice browned with a crispy, slightly charred cheese crust. Cream sauce bubbles gently around the edges and between the potato layers, with visible specks of black pepper and small sprigs of fresh green thyme scattered on top. The surface has a smooth, melted cheese texture with uneven golden patches from baking. The dish is placed on a white marbled texture background. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I make this potato gratin the night before?

Yes, you can assemble the gratin the night before and refrigerate it. It’s best to bake it just before serving to keep the potatoes from browning and to achieve a fresh, creamy texture. Some cooks prefer to bake it fully and reheat the next day with a fresh layer of cheese on top.

What type of potatoes work best for gratin?

Starchy potatoes like Russets or Yukon Golds are ideal because they become tender and absorb the creamy sauce well without becoming mushy.