- Salt
- 6 ounces slab bacon, in 1 piece
- 2 tablespoons extra-virgin olive oil, plus more if needed
- 2 large yellow onions, sliced 1/2 inch thick (about 3 cups)
- 1½ cups hot Chicken Stock or canned reduced-sodium chicken broth, or as needed
- 1 pound linguine
- 3 egg yolks
- 1 cup freshly grated Parmigiano-Reggiano cheese
- Coarsely ground black pepper
- Bring 6 quarts of salted water to the boil in an 8-quart pot over high heat.
- Remove the rind, if necessary, from the bacon. Cut the bacon into 1/4-inch slices, then cut the slices crosswise into 1/4-inch strips. Heat the olive oil in a large, heavy skillet over medium heat. Add the bacon and cook, stirring, until the bacon is lightly browned but still soft in the center, about 6 minutes.
- The amount of fat in the skillet will vary depending on the bacon. If there is more than 3 to 4 tablespoons of fat in the pan, pour off the excess. If there is less than 3 to 4 tablespoons, add enough olive oil to measure that amount. Add the onions and cook until wilted but still crunchy, about 4 to 5 minutes. Add the stock, bring to a boil, and adjust the heat to a lively simmer. Cook until the liquid is reduced by about half.
- Meanwhile, stir the linguine into the boiling salted water. Return to a boil, stirring frequently. Cook the pasta, semi-covered, stirring occasionally, until done, about 8 minutes.
- Ladle off about a cup of the pasta-cooking water. If the skillet is large enough to accommodate the sauce and pasta, fish the pasta out of the boiling water with a large wire skimmer and drop it directly into the sauce in the skillet. If not, drain the pasta, return it to the pot, and pour in the sauce. Bring the sauce and pasta to a boil, stirring to coat the pasta with sauce. Check the seasoning, adding salt if necessary. If necessary, add as much chicken stock or pasta-cooking water as needed to make enough sauce to coat the pasta generously. Remove the pan from the heat and add the egg yolks one at a time, tossing well after each. (A salad fork and spoon work well for this.) Add the grated cheese, then the black pepper, tossing well, and serve immediately in warmed bowls.