01 -
Place ricotta in a fine mesh sieve over a bowl or sink and drain for 15 minutes to 2 hours, until firm and able to hold its shape.
02 -
Cover spinach with boiling water in a large heatproof bowl and let wilt for 1 to 2 minutes. Transfer to ice water, then squeeze out all excess moisture and chop finely.
03 -
In a large mixing bowl, combine drained ricotta, chopped spinach, egg, Parmesan, bread crumbs, lemon zest, nutmeg, and kosher salt. Mix well until homogenous.
04 -
Add all-purpose flour in two batches, folding gently until just combined to prevent toughness.
05 -
Dust a quarter sheet pan with 2 tablespoons of semolina flour. Use a 3-tablespoon scoop to portion dough into 20 pieces. Place on pan and dust with another 2 tablespoons of semolina flour.
06 -
Roll each portion into a ball, dusting with semolina as needed. Refrigerate uncovered for at least 1 hour and up to 12 hours for best texture.
07 -
Bring a large pot of water to a rolling boil, salt generously with kosher salt. Test-boil one gnudi until it floats, about 4 minutes, then boil 1 more minute. Boil remainder in batches until all are cooked.
08 -
On medium heat, melt 2 tablespoons butter with Calabrian chilies in a large sauté pan. Add 1/4 cup pasta water, stir to emulsify. Gradually melt in remaining butter, adding a splash of pasta water as needed for a smooth, spicy sauce.
09 -
Turn off heat and add cooked gnudi to the pan, tossing gently to coat in sauce. Serve immediately.