How to Make It
Put the oil and onion in a large skillet and cook over moderately high heat, stirring frequently, until the onion is pale gold. Add the pancetta and rosemary and cook, stirring occasionally, until the pancetta fat is rendered; the pancetta should remain soft. Add the lamb and cook until browned, 5 minutes. Season with salt and pepper and stir. Add the wine and simmer until evaporated, 10 minutes. Add the tomatoes and simmer gently, stirring from time to time, until the fat begins to separate from the sauce, 15 minutes.
Meanwhile, fill a large pot with 4 quarts of water and bring to a boil. Add 1 1/2 tablespoons of coarse salt, cover and return to a boil.
Add the pasta to the pot and stir rapidly with a wooden spoon. Cover and bring back to a boil. Uncover and cook the pasta, stirring frequently, until it is al dente.
Drain the pasta and immediately transfer it to a warmed bowl. Toss with the lamb sauce and the 1/3 cup of grated cheese. Serve at once, passing additional cheese at the table.