Sweet Potato Gnocchi with Fried Sage and Pine Nuts
Serves 6-8

Frying sage leaves is easy and provides a real wow factor. The sage and pine nuts make an ideal foil for these pillowy gnocchi.
 
•    600g russet (baking potatoes)
•    800g sweet potato
•    1 large egg
•    1/2 teaspoon grated nutmeg
•    1/3 cup grated Parmigiano-Reggiano plus more for serving
•    1 1/2 to 2 cups all-purpose flour plus more for dusting
•    1/3 cup extra-virgin olive oil
•    1 cup sage leaves (from 1 bunch)
•    1/3 cup pine nuts
•    2 tablespoons unsalted butter

Make gnocchi:

•  Preheat oven to 230°C with rack in middle.

• Pierce russet and sweet potatoes in several places with a fork, then bake in a 4-sided sheet pan until just tender, 45 minutes to 1 hour.

• Cool potatoes slightly, then peel and force through ricer into sheet pan, spreading in an even layer. Cool potatoes completely.

• Lightly flour 2 or 3 large baking sheets or line with parchment paper.

• Beat together egg, nutmeg, 1 tsp salt, and 1/2 tsp pepper in a small bowl.

• Gather potatoes into a mound in sheet pan, using a pastry scraper if you have one, and form a well in center.

• Pour egg mixture into well, then knead into potatoes. Knead in cheese and 11/2 cups flour, then knead, adding more flour as necessary, until mixture forms a smooth but slightly sticky dough. Dust top lightly with some of flour.

• Cut dough into 6 pieces. Form 1 piece of dough into a 1/2-inch-thick rope on a lightly floured surface. Cut rope into 1/2-inch pieces. Gently roll each piece into a ball and lightly dust with flour.

• Repeat with remaining 5 pieces of dough.

• Turn a fork over and hold at a 45-degree angle, with tips of tines touching work surface. Working with 1 at a time, roll gnocchi down fork tines, pressing with your thumb, to make ridges on 1 side. Transfer gnocchi as formed to baking sheets.

Fry sage leaves and pine nuts:

• Heat oil in a 12-inch heavy skillet over medium heat until it shimmers. Fry sage leaves in 3 batches, stirring, until they turn just a shade lighter and crisp (they will continue to crisp as they cool), about 30 seconds per batch. Transfer to paper towels to drain. Season lightly with salt.

• Fry pine nuts, stirring, until golden and crisp, for about 60 seconds. Transfer to paper towels to drain. Season lightly with sea salt. Reserve oil in skillet.

Make sauce:

• Add butter to oil in skillet with 1/2 tsp salt and cook until golden-brown, 1 to 2 minutes. Remove from heat.

Cook gnocchi:

• Add half of gnocchi to a pasta pot of well-salted boiling water and stir. Cook until they float to surface, about 3 minutes. Transfer with a slotted spoon to skillet with butter sauce. Cook remaining gnocchi in same manner, transferring to skillet as cooked.

• Heat gnocchi in skillet over medium heat, stirring to coat.

• Serve sprinkled with fried sage, pine nuts and grated cheese.