Truffle Potato Gratin with Gruyere Cream Skillet

This truffle potato gratin turns a classic comfort dish into something special. Thinly sliced Yukon Gold potatoes and clean leeks are layered in a buttered cast iron skillet, then baked under a bubbling garlic thyme cream and a blanket of aged Gruyere.

The result is a golden, crispy-topped gratin with a creamy, tender interior that pulls apart in cheesy, satisfying strands. It's the kind of side dish that steals the spotlight at any dinner table, yet it comes together with simple ingredients and a straightforward method.

Potato gratin is a beloved classic, but this version takes it up a notch with a few thoughtful touches. Using a cast iron skillet means the edges get wonderfully crisp while the center stays luscious and creamy. The leeks add a gentle oniony sweetness that pairs beautifully with the earthy truffle oil and nutty Gruyere.

The garlic thyme cream is poured over the layers before baking, infusing every slice with flavor. This recipe is straightforward enough for a weeknight yet elegant enough for company. Serve it alongside roasted meat, fish, or a simple green salad for a complete meal.

Ingredients

Why this recipe works

The method here is designed to produce a gratin with both a crispy top and a creamy interior. Slicing the potatoes paper-thin ensures they cook through evenly without becoming mushy, while the overlapping layers create a cohesive, sliceable structure.

The leeks add moisture and flavor without watering down the cream, and the Gruyere melts into a golden, stretchy crust that contrasts beautifully with the tender potatoes. Baking covered first steams the potatoes gently, then removing the foil allows the top to brown and crisp.

The choice of a cast iron skillet is intentional: it conducts heat evenly and retains it well, which helps the edges of the gratin develop a delicious caramelized crust.

The heavy cream and cheese create a rich sauce that clings to each potato slice, while the truffle oil adds a subtle, earthy aroma that elevates the dish without overpowering it. Resting the gratin before serving allows the cream to settle and the layers to firm up slightly, making it easier to serve neat, beautiful portions.

Notes and substitutions

Yukon Gold potatoes are ideal for this gratin because they have a buttery flavor and hold their shape during baking. If you prefer, you can use Russets, but they may break down a bit more. The leeks should be cleaned thoroughly—they often trap dirt between their layers. Slice them thinly so they cook through and meld into the dish. Aged Gruyere provides a nutty, complex flavor; if you can't find it, a good Swiss cheese or sharp white cheddar works well.

Truffle oil is optional but adds a lovely earthy note. Use a high-quality oil and add it to the cream just before pouring, as heat can diminish its aroma. If you don't have a cast iron skillet, a 10-inch ovenproof skillet or a baking dish will work, though the crispy edges may be less pronounced. The gratin can be assembled a few hours ahead and refrigerated, but add 10 minutes to the covered baking time if starting from cold.

• Yukon Gold potatoes: Russet or red potatoes (adjust cooking time slightly)
• Aged Gruyere: Swiss cheese, Emmental, or sharp white cheddar
• Heavy cream: Half-and-half mixed with 2 tbsp melted butter (for a lighter version)
• Truffle oil: A few drops of truffle-infused olive oil or omit entirely

Equipment

• 10-inch cast iron skillet
• Box grater
• Mandoline or sharp chef's knife
• Cutting board
• Chef's knife
• Medium saucepan
• Wooden spoon
• Aluminum foil