Ingredients
- 3 lb Yukon Gold potatoes
- 2 cups heavy cream
- 1 cup whole milk
- 4 oz Gruyère cheese grated (about 1 ½ cups)
- 2 oz Pecorino cheese finely grated (about ½ cup)
- 3 oz speck thinly sliced
- 10 fresh sage leaves
- 4 cloves garlic confit in olive oil
- 2 bay leaves
- pinch freshly grated nutmeg
- 1 teaspoon kosher salt
- ½ teaspoon black pepper
- 2 tablespoon unsalted butter
Method
Infuse the Cream
- In a saucepan, combine cream, milk, bay leaves, smashed garlic confit, nutmeg, salt, and pepper. Warm over medium heat until just steaming. Remove from heat and let steep 10 minutes; discard bay leaves. The cream will carry aroma before it ever touches the potatoes.
Crisp the Speck and Sage
- Arrange speck slices on a parchment-lined sheet pan. Bake at 375 °F for 10–12 minutes until deep amber and crisp. Cool on paper towels until brittle, then break into shards.
- In a small pan, melt butter and fry sage leaves until crisp, about 30 seconds. Reserve butter and leaves separately.
Assemble the Gratin
- Preheat oven to 375 °F. Brush baking dish with some of the sage butter.
- Arrange one-third of the potatoes in an even layer and sprinkle with one-third of the Gruyère. Repeat twice, finishing with remaining Gruyère and all Pecorino on top for crisp texture.
- Pour the warm infused cream evenly over the potatoes and press down lightly to submerge.
- Cover with foil and bake 45 minutes.
- Uncover, brush with remaining sage butter, and bake 25 minutes more until deep gold and bubbling.
To Plate
- Rest 10 minutes before cutting.
- Top with crisp speck shards and sage leaves just before serving. The cheese melts through the layers, the speck adds smoke and salt, and the sage finishes it with butter and aroma.