Truffle Potato Gratin with Gruyere Cream Skillet Tips, FAQ & printable recipe

Tips for success

For the crispiest edges, press the potato layers down firmly before baking so they are compact. The cream should just cover the top layer—if there's extra, reserve it and add a little more during the last 10 minutes if needed.

Use a mandoline for perfectly uniform slices, which ensures even cooking. If you don't have a mandoline, a sharp chef's knife and patience work fine.

To make this gratin ahead, assemble it completely, cover, and refrigerate for up to 24 hours. When ready to bake, add about 10 minutes to the covered baking time.

The gratin can also be frozen after baking, but the texture may be slightly softer upon reheating. For a golden, bubbly top, place the skillet under the broiler for 1-2 minutes after baking, watching closely to avoid burning.

Variations

• Herb and Garlic Variation: Replace the thyme with 1 teaspoon of fresh rosemary and 1 teaspoon of chopped sage. Add an extra clove of garlic to the cream for a more pronounced garlic flavor. Omit the truffle oil for a simpler, herb-forward gratin.
• Bacon and Caramelized Onion: Cook 4 slices of bacon until crisp, then crumble. Caramelize 1 large onion in the bacon fat until golden. Layer the potatoes with the caramelized onion and bacon instead of leeks, and use the bacon fat to butter the skillet.
• Cheddar and Chive Gratin: Substitute the Gruyere with sharp white cheddar. Add 2 tablespoons of chopped fresh chives to the cream mixture and sprinkle more on top before serving. Omit the truffle oil for a more straightforward cheese flavor.
• Root Vegetable Gratin: Replace half of the potatoes with thinly sliced parsnips or celery root. The root vegetables add a subtle sweetness and a slightly different texture. Keep the leeks and Gruyere, and follow the same layering method.

Storage and make-ahead

Fridge

Store in an airtight container in the refrigerator for up to 4 days. Reheat gently before serving.

Freezer

Freeze the baked gratin in a freezer-safe container for up to 2 months. Thaw overnight in the refrigerator before reheating.

Reheat

Reheat in a 350°F (175°C) oven for 15-20 minutes, or until hot and bubbly. Add a splash of cream if the gratin seems dry.

Store leftover gratin in an airtight container in the refrigerator for up to 4 days. The gratin will firm up as it cools. To reheat, place portions in a 350°F (175°C) oven for 10-15 minutes, or microwave in 30-second bursts until heated through. For best texture, reheat in the oven to restore some crispness to the top.

This gratin can be assembled up to 24 hours in advance and stored in the refrigerator. Follow the recipe through the layering step, then cover and chill.

When ready to bake, remove from the fridge and let sit at room temperature for 30 minutes, then bake as directed, adding 10 minutes to the covered time. The gratin can also be fully baked, cooled, and refrigerated for up to 3 days; reheat in a 350°F (175°C) oven until hot.

Serving ideas

Serve this gratin as a show-stopping side dish alongside roasted chicken, beef tenderloin, or grilled fish. It also shines as a vegetarian main when paired with a crisp green salad and a glass of white wine.

The creamy, cheesy layers are rich and satisfying, so a little goes a long way. Portion it with a large spoon, making sure to include some crispy edges in each serving.

For a festive presentation, garnish with fresh thyme sprigs and a sprinkle of flaky sea salt just before serving. The gratin pairs beautifully with other roasted vegetables, crusty bread, or a simple arugula salad with lemon vinaigrette. Leftovers can be served cold or reheated, and they make a delicious addition to a brunch spread alongside eggs and fruit.

Frequently asked questions

Recipe card

Truffle Potato Gratin with Gruyere Cream Skillet

Prep 20 minCook 55 minRest 10 minTotal 1 h 25 minServes 6

Ingredients

• 2 tbsp unsalted butter, softened
• 2 lb Yukon Gold potatoes, thinly sliced
• 2 medium leeks, white and light green parts, thinly sliced
• 8 oz aged Gruyere cheese, grated
• 2 cups heavy cream
• 3 cloves garlic, minced
• 1 tbsp fresh thyme leaves, plus more for garnish
• 1 tsp truffle oil (optional)
• 1 tsp kosher salt
• 1/2 tsp black pepper, freshly ground

Instructions

1. Heat the oven to 375°F (190°C). Butter the bottom and sides of a 10-inch cast iron skillet generously. Using a mandoline or a sharp knife, slice the Yukon Gold potatoes into paper-thin rounds, about 1/8-inch thick. Clean the leeks thoroughly, then slice them thinly crosswise, using only the white and light green parts. Grate the aged Gruyere on the large holes of a box grater into a bowl.
2. In a small saucepan, combine the heavy cream, minced garlic, fresh thyme leaves, kosher salt, and black pepper. Warm over medium heat, stirring occasionally, until the mixture is steaming and small bubbles form around the edges. Do not let it boil. Remove from the heat and stir in the truffle oil, if using. Set aside.
3. Arrange a single layer of potato rounds in the buttered skillet, overlapping them in a tight spiral. Scatter a handful of sliced leeks over the potatoes, then sprinkle with a portion of the grated Gruyere. Repeat the layers—potatoes, leeks, cheese—until all ingredients are used, finishing with a layer of potatoes. Pour the warm garlic thyme cream evenly over the top, pressing down gently with a spatula to ensure the cream reaches every layer.
4. Cover the skillet tightly with aluminum foil and place it in the preheated oven. Bake for 35 minutes, then remove the foil and continue baking for 15 to 20 minutes more, until the top is golden brown and the potatoes are tender when pierced with a knife. The cream should be bubbling and slightly reduced.
5. Remove the skillet from the oven and let the gratin rest for 10 minutes. This allows the cream to set slightly and makes serving easier. Scatter fresh thyme leaves over the top before serving. Use a spoon or spatula to lift out portions, pulling up the crispy cheese edges for maximum effect.

Contains: milk

Estimated nutrition per serving

Calories

480

Protein

14 g

Carbohydrates

30 g

Fat

34 g

Automatic estimate from the ingredient list, not laboratory-verified.