Name: Rich Potato Gratin with Gruyère and Herb Cheese Sauce Recipe
Prep time: 20 min
Cook time: 50 min
Total time: 1 h 10 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 (such as Kerrygold); 1 small onion, minced; 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 that combines thinly sliced potatoes with a creamy, cheesy sauce. With layers of tender potatoes and melted gruyere, this gratin is an irresistible side perfect for family dinners or special occasions.

Two white oval baking dishes filled with layered potato gratin sit on a white marbled texture. Each dish contains thin slices of golden-brown potatoes layered with creamy sauce and melted cheese, topped with finely chopped green herbs that add small patches of color. The potatoes have a slightly crispy, browned top layer, showing some texture from baking. A fork is placed inside the closer dish, lifting a few slices, showing the creamy, soft layers beneath the crust. The overall impression is warm, rich, and smooth with light brown and yellow tones. 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 (unsalted recommended)
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 for even cooking. Mince the onion, grate the garlic, chop the thyme, and grate all the gruyere cheese. Having everything ready helps you 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, sautéing gently for 3-5 minutes until the onion softens and becomes translucent without browning.
Step 3: Sprinkle the flour over the aromatic mixture and cook for 1 minute, stirring constantly to make a roux. Slowly pour in the milk while whisking vigorously to avoid lumps. Continue whisking for 1-2 minutes until the sauce thickens. Remove from heat and stir in 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. Arrange half the sliced potatoes in an overlapping pattern over the sauce, then pour half of the remaining sauce over them. Add the remaining potatoes in another layer and pour the rest of the sauce on top, filling any gaps.
Step 5: Sprinkle the remaining 1 cup of grated gruyere cheese evenly over the top. Bake at 350°F for 45-60 minutes until potatoes are tender and the top is lightly golden. For a deeper crust, use the broiler for 2-3 minutes at the end, watching carefully. Let rest for 10 minutes before serving to set the layers.

Tips & Variations

Use heavy cream instead of milk for an even richer sauce.
Try adding a splash of white wine to the sauce for extra depth.
For a gluten-free version, substitute the flour with a gluten-free alternative like rice flour or cornstarch.
Feel free to mix in fresh herbs such as rosemary or sage instead of thyme for different flavor profiles.
Make sure to slice potatoes uniformly thin to ensure they cook evenly and become tender.

Storage

Store leftover gratin covered in the refrigerator for up to 3 days. Reheat in the oven at 350°F until warmed through to retain the creamy texture. Avoid microwaving as it can make the potatoes rubbery.

How to Serve

The image shows a close-up of a creamy, layered potato gratin served on a white plate, placed on a white marbled surface. It has several thin layers of pale yellow potatoes visible through a thick, bubbling, golden-brown cheese crust on top. The cheese layer has a slightly crispy texture with browned spots and small green herbs sprinkled on it. A silver fork rests on the left side of the plate, partially touching the gratin. The dish looks soft, rich, and cheesy, with small flecks of herbs throughout the layers. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I prepare the gratin ahead of time?

Yes, you can assemble the dish and refrigerate it uncovered for a few hours before baking. Just bring it to room temperature before putting it in the oven for more even cooking.

What potatoes work best for gratin?

Starchy potatoes like Russets or Yukon Golds work well as they become tender and absorb the sauce, creating a creamy texture without falling apart.