Spaghetti alla Carbonara

Directions

1. 1
   Cut guanciale or pancetta into 1/3-inch dice, then cook in a deep 12-inch heavy skillet over moderate heat, stirring, until fat begins to render, 1 to 2 minutes.
2. 2
   Add onion and cook, stirring occasionally, until onion is golden, about 10 minutes.
3. 3
   Add wine and boil until reduced by half, 1 to 2 minutes.
4. 4
   Cook spaghetti in a 6- to 8-quart pot of boiling salted water until al dente.
5. 5
   While pasta is cooking, whisk together eggs, Parmigiano-Reggiano , Pecorino Romano (1/3 cup), 1 teaspoon coarsely ground black pepper, and 1/4 teaspoon salt in a small bowl.
6. 6
   Drain spaghetti in a colander and add to onion mixture, then toss with tongs over moderate heat until coated.
7. 7
   Remove from heat and add egg mixture, tossing to combine.
8. 8
   Serve immediately.