Classic Potato Gratin Dish

This classic potato gratin transforms simple ingredients into a luxurious side dish perfect for both weeknight dinners and special occasions. The combination of thinly sliced potatoes layered with creamy sauce and melted cheese creates comfort food at its finest.

I first made this gratin for a dinner party where I wanted to elevate ordinary potatoes into something special. The dish disappeared within minutes, and now it's requested at every family gathering no matter the season.

Ingredients

• Butter: Forms the rich base for the creamy sauce that binds everything together
• Onion and garlic: Provide aromatic flavor that perfumes the entire dish without overwhelming it
• Fresh thyme: Adds the perfect herbal note that cuts through the richness
• All-purpose flour: Thickens the sauce to the ideal consistency for coating the potatoes
• Milk or heavy cream: Creates the silky sauce that becomes the soul of any good gratin
• Gruyere cheese: Offers the perfect melting texture with a nutty depth traditional in this dish
• Nutmeg: Brings a subtle warmth that enhances the dairy flavors
• Potatoes: Provide the hearty foundation with russet or Yukon gold varieties working equally well

Step-by-Step Instructions

Create The Base:

Melt butter over medium heat then add diced onion and cook until translucent and soft which takes about 3 to 5 minutes. This slow cooking develops sweetness in the onions rather than browning them quickly.

Add Aromatics:

Incorporate minced garlic and chopped thyme into the softened onions cooking just until the garlic becomes fragrant which takes approximately one minute. Take care not to brown the garlic which can introduce bitterness.

Make The Roux:

Sprinkle flour over the onion mixture and stir constantly until it coats everything evenly and begins to turn light golden which takes about one minute. This cooking removes the raw flour taste while creating the foundation for thickening.

Create The Sauce:

Pour in the milk or cream gradually while stirring constantly to prevent lumps from forming. Continue cooking and stirring until the sauce thickens enough to coat the back of a spoon which takes one to two minutes.

Add Cheese:

Reduce heat to low before adding half a cup of shredded Gruyere cheese stirring gently until completely melted. Season with nutmeg salt and pepper adjusting to your taste preferences.

Layer The Potatoes:

Spread a thin layer of sauce on the bottom of your baking dish then begin arranging potato slices in layers adding sauce between each layer. For a more efficient method you can dip each slice into the sauce before placing in the dish.

Final Assembly:

Pour any remaining sauce over the arranged potatoes ensuring every slice receives some coverage then sprinkle the remaining Gruyere cheese evenly across the top for a golden brown crust.

Bake To Perfection:

Place in a preheated 350°F oven and bake until potatoes become fork tender and the top turns golden and bubbly which typically takes between 45 to 60 minutes depending on your oven.

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The scent of this potato gratin baking has become synonymous with comfort in our home. I distinctly remember making this during a particularly harsh winter storm when we lost power. We finished baking it on our gas stovetop in a covered Dutch oven and enjoyed it by candlelight a memory my family still talks about years later.

The Art Of Slicing

Creating uniformly thin potato slices is crucial for even cooking. A mandoline slicer produces the ideal thickness of about 1/8 inch ensuring each slice cooks at the same rate. If using a knife take your time to maintain consistency. Soaking the sliced potatoes in cold water for 20 minutes before assembling removes excess starch and prevents discoloration but be sure to pat them completely dry before using.

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Perfect Cheese Selection

While Gruyere is the traditional choice for potato gratin this dish welcomes experimentation. Consider combining cheeses for complex flavor profiles. A mixture of sharp cheddar with smoked gouda creates a bold American twist while blending fontina with parmesan offers an Italian inspired variation. The key is choosing cheeses that melt smoothly rather than those that separate when heated.

Serving Suggestions

This luxurious potato gratin pairs beautifully with roasted meats particularly beef tenderloin or leg of lamb where the creamy potatoes balance the richness of the meat. For a complete meal serve alongside a simple green salad dressed with a bright vinaigrette to cut through the richness. When serving as part of a larger spread allow the gratin to rest for 15 minutes before cutting which helps portions hold their shape better on the plate.

The French Connection

This dish traces its origins to the Alpine regions of France where dairy farming produces exceptional butter and cheese. Traditional dauphinoise potatoes the closest French relative to this gratin typically contains no cheese focusing instead on the perfect marriage of potatoes and cream. Our version with the addition of Gruyere represents the evolution of the dish as it traveled beyond French borders becoming a beloved comfort food throughout Europe and eventually around the world.

Recipe FAQs

→ Can I make potato gratin ahead of time?

Yes, you can assemble potato gratin up to 24 hours ahead and refrigerate it covered. Before baking, let it sit at room temperature for 30 minutes. You may need to extend the baking time by 10-15 minutes if baking from refrigerated. Alternatively, you can fully bake it, refrigerate, and reheat covered at 350°F until hot throughout.

→ What's the best way to slice potatoes for gratin?

For the best texture and even cooking, slice potatoes to a uniform thickness of about 1/8 inch (3mm). A mandoline slicer is ideal for this task, ensuring consistent thin slices. If using a knife, take your time and work with a sharp blade for the most precise cuts. Uniformly thin slices ensure the potatoes cook evenly throughout the dish.

→ Which potatoes work best for gratin?

Both starchy Russet potatoes and waxy Yukon Gold potatoes work excellently for gratin. Russets break down more during cooking, absorbing the creamy sauce and creating a softer texture. Yukon Golds hold their shape better while still becoming tender, with a naturally buttery flavor that enhances the dish. Either choice or a combination of both will produce delicious results.

→ How can I tell when my potato gratin is done?

A perfectly cooked potato gratin has several indicators: the top should be golden brown and bubbling around the edges, the cheese should be melted and slightly crispy, and most importantly, a knife inserted into the center should slide through the potato layers without resistance. If there's any firmness when piercing the potatoes, continue baking until they're completely tender.

→ What can I serve with potato gratin?

Potato gratin pairs beautifully with roasted meats like beef tenderloin, prime rib, roast chicken, or ham as a sophisticated side dish. For balance, serve alongside green vegetables such as roasted asparagus, Brussels sprouts, or a simple green salad with a bright vinaigrette. The rich, creamy texture of gratin complements both elegant holiday meals and simple weeknight dinners featuring grilled proteins.

→ Can I use pre-shredded cheese for potato gratin?

While convenient, pre-shredded cheese often contains anti-caking agents that can prevent proper melting and affect the texture of your sauce. For the creamiest, smoothest results, it's best to buy blocks of Gruyere or other cheeses and shred them yourself just before using. Freshly grated cheese also typically has better flavor than pre-packaged options.