Potato Gratin with Pancetta & Leeks

From Melt, Stretch, & Sizzle: The Art of Cooking Cheese by Tia Keenan, Rizzoli New York, ©2018. Reprinted with permission.

• Servings: 6 to 10, depending on when served during the meal

This luscious recipe is from Melt, Stretch, & Sizzle, by cheese expert and flavor bomb genius Tia Keenan, who suggested these three cheeses for great results: Taleggio, Meadow Creek Dairy Grayson, Quadrello di Bufala.

She also wrote its introduction:

I prefer using supple, slightly funky washed-rind cheeses in gratins. Since they shouldn’t actually use that much cheese, I figure a whiffy one won’t threaten the harmony of the dish. Cream does quite a bit of the heavy lifting in this gratin. If the cream is the garment, pungent cheese is the statement necklace that really makes the outfit. But gratins can also be a great way to use up a hodgepodge of leftover cheese, so don’t get too caught up in my mixed metaphors: use what you have, a good melter for inside and something aged that’ll crisp up nicely on top.

Ingredients

• 6 tablespoons unsalted butter, plus more for greasing the pan
• 4 ounces pancetta, finely diced
• 2 leeks, white and light green parts only, washed and thinly sliced
• 2 sprigs fresh thyme
• 2 garlic cloves, minced
• 1 teaspoon kosher salt
• 1 pound russet potatoes (about 2 medium), peeled and sliced 1/8-inch thick
• 1 pound Yukon Gold potatoes (about 2 medium), peeled and sliced 1/8-inch thick
• Freshly ground black pepper
• 6 ounces Taleggio, cubed
• 1 1/2 cups heavy cream
• 2 tablespoons grated Parmigiano Reggiano

Directions

1. Preheat the oven to 375°F. Butter a 9 x 13-inch glass baking dish.
2. In a medium sauté pan over medium heat, melt 1 tablespoon of the butter. Add the pancetta and cook until crisp, about 5 minutes. Remove with a slotted spoon to a small bowl and set aside. In the rendered fat, sauté the leeks and the thyme until the leeks are soft and bright green, about 5 minutes. Add the garlic and salt and sauté until fragrant, about 2 minutes. Remove the pan from the heat and discard the thyme.
3. Cut the remaining 5 tablespoons butter into 1⁄2-inch cubes. Shingle the potatoes in a single layer on the bottom of the baking dish, alternating slices of each type, then add a few grindings of black pepper. Scatter about 2 tablespoons of the leek mixture onto the potatoes, then sprinkle on some pancetta, 5 or 6 cubes of Taleggio, and 4 or 5 cubes of butter. Repeat, layering the sliced potatoes, leek mixture, pancetta, Taleggio, and butter, and seasoning with freshly ground black pepper every other layer. Finish with a potato layer and press the layers down into the dish (you should have about 5 layers). Pour the cream over the potatoes, dot with the remaining butter, and sprinkle with the Parmigiano Reggiano.
4. Transfer the baking dish to the oven and bake until bubbling, browned, and crispy on top, about 60 minutes. Let cool for 20 minutes before serving—the gratin definitely “comes together” during this time—and so you don’t burn your mouth, either.