How to Make It
Preheat the oven to 400°. Prick the potatoes with a fork, wrap in foil and bake until tender, 1 hour. Let stand until just cool enough to handle, about 10 minutes. Peel the potatoes and cut into large chunks. Press through a ricer onto a work surface; you should have about 6 loosely packed cups. Gently spread the potatoes into a 10-by-18-inch rectangle. Scrape the egg yolks on top and sprinkle with the 3 cups of flour, the cheese, salt, pepper and nutmeg. Using a pastry scraper, swiftly chop the ingredients together. Knead gently until the dough comes together in a smooth ball. Cut into 8 wedges and cover with a kitchen towel.
Lightly dust 2 rimmed baking sheets with flour. Roll 1 wedge of gnocchi dough into a 3/4-inch-thick rope, about 18 inches long. Using a knife, cut the rope into 3/4-inch pieces and transfer to a prepared baking sheet. Repeat with the remaining dough. Cover the gnocchi with plastic wrap and refrigerate until firm, at least 30 minutes.
Working over a medium bowl, coarsely grate the tomatoes on a box grater; discard the skins. You should have about 1 3/4 cups of tomato puree.
In a deep medium skillet, cook the chorizo over moderate heat, breaking up any clumps, until beginning to brown, 8 to 10 minutes. Scrape the chorizo onto a plate.
Heat the oil in the skillet. Add the onion, season with a generous pinch each of salt and black pepper and cook over moderate heat until golden, 5 to 7 minutes. Add the carrot and garlic and cook, stirring, until softened, about 2 minutes. Stir in the tomato paste. Deglaze the skillet with the wine, scraping up any browned bits. Cook until the wine has reduced by two-thirds, about 3 minutes. Return the chorizo to the skillet with the fresh tomato puree, bay leaf, sugar and chicken stock. Bring the sauce to a boil, then simmer over moderately low heat, stirring, until reduced by half, about 45 minutes. Stir in the 1/4 cup of cheese and the minced oregano and season with salt and black pepper. Keep warm.
In a pot of salted boiling water, cook the gnocchi in 3 batches until tender, about 6 1/2 minutes per batch. The gnocchi will float to the top after 1 to 2 minutes; keep cooking them. Using a slotted spoon, transfer the gnocchi to a warm platter. Spoon the chorizo sauce on top and garnish with grated cheese, oregano sprigs and red pepper.