Ricotta Gnocchi Gratin

In the bowl of a stand mixer fitted with the dough hook, mix the ricotta with the 2/3 cup of Parmigiano, the whole egg, egg yolk, lemon zest, nutmeg, 2 teaspoons of kosher salt and 1/2 teaspoon of pepper at medium speed until blended. With the machine on low, gradually add the 1 1/4 cups of flour until incorporated. Beat at medium speed until a tacky dough forms, about 1 minute. Scrape the dough out onto a floured work surface and pat into a mass. Dust the top with flour, then wrap in plastic and refrigerate for 30 minutes.

Line a baking sheet with wax paper and dust with flour. On a floured surface, cut the dough into 4 pieces; gently roll each into a 3/4-inch-thick rope. Cut the ropes into 1-inch lengths and transfer to the baking sheet.

Grease a large rimmed baking sheet with oil. In a large pot of simmering salted water, cook one-third of the gnocchi over moderate heat until they rise to the surface, then cook for 2 minutes longer. Using a slotted spoon, transfer to the prepared baking sheet. Repeat with the remaining gnocchi.

Preheat the oven to 200°. In a large skillet, cook one-third of the pancetta in 1 tablespoon of the oil over moderate heat, stirring occasionally, until the fat is rendered but the pancetta is not crisp, 3 to 5 minutes. Stir in 3 tablespoons of the butter and cook, stirring, until it just starts to brown and smell nutty, about 3 minutes. Add 10 sage leaves; cook until crisp, 20 seconds.

Add one-third of the gnocchi and cook, undisturbed, until golden on the bottom, 2 to 3 minutes. Using a metal spatula, flip the gnocchi and cook until browned, about 2 minutes longer. Stir in 2 teaspoons of the lemon juice and a pinch of the orange zest; season with salt and pepper. Using a spatula or slotted spoon, transfer the gnocchi, pancetta and sage to a large ovenproof serving dish. Spoon 2 tablespoons of the fat from the skillet over the gnocchi; keep warm in the oven. Pour off the remaining fat from the skillet. Repeat the whole process 2 more times. Sprinkle Parmesan over the gnocchi and serve.