- 2 lb Russet potatoes, scrubbed
- 2 large egg yolks
- About 1/2 cup sifted all-purpose flour, plus more for dusting
- 1 tsp salt
- 1/3 cup whole milk
- 3 oz Taleggio cheese rind removed and crumbled
- 2 oz Gorgonzola, rind removed and crumbled
- 3 oz Parmigiano-Reggiano, grated, plus more for grating
- 4 oz Gruyere rind removed and grated
- Salt and freshly ground pepper
Preheat oven to 450 degrees. Poke potatoes with fork and place on an oven rack and cook until completely tender throughout when pierced with a fork, 45 minutes to 1 hour.
Transfer potatoes to a work surface. Using tongs to hold hot potatoes, slice each in half lengthwise.
Using a spoon, scoop potato flesh into a small bowl. Using a ricer, rice potatoes onto a clean work surface, spreading it into a rectangular, even layer. Allow steam to escape for a few minutes.
Drizzle egg yolks all over. Scoop 1/4 cup of flour into a fine-mesh sieve and tap to dust flour all over potatoes. Using a pastry blender or bench scraper, chop down repeatedly all over to cut flour and egg into potato.
Using a bench scraper, gather up potato mass and pat into a loose ball. Press ball flat with hands, then fold in half using bench scraper and press down again. Scoop remaining 1/4 cup flour into sieve and dust all over potato dough. Continue to gently fold and press, just until a uniform dough comes together. Dust potato dough all over with flour and gently form into a log.
Clean work area well and dust with fresh flour. Using the bench scraper, slice off a 2″-thick portion of dough at a time and roll into snake about 1/2″ thick. Try to use your palms more than your fingers along with a light touch, and dusting as necessary with flour to prevent sticking.
Using bench scraper, cut snake into 1″ portions. Transfer gnocchi to a well-floured baking sheet and repeat with remaining dough.
Meanwhile, in a frying pan over medium heat, warm milk. Add cheeses, salt and pepper, reduce heat to low and stir occasionally until cheeses melt.
Bring a large pot of salted water to a boil over high heat. Working in batches, add gnocchi and cook until they float to the surface. Let cook an additional 30 seconds and, using a spider or slotted spoon, transfer gnocchi to the cheese sauce. Repeat with remaining gnocchi.
Adapted from Serious Eats