Warm the bacon in the olive oil in a 12-inch skillet or 3-quart sauté pan over low heat. It should gradually render a little fat, which will mix with the oil.
Meanwhile, lightly beat the eggs with the ricotta.
Drop the pasta into 6 quarts rapidly boiling water seasoned with a scant 2 tablespoons salt (a little more if using kosher salt). Stir and cook until al dente (still firm to the tooth).
When the pasta is about 1 minute from being al dente, add the peas or favas to the water, and raise the heat under the bacon. Cook the bacon until it is just crispy on the edges but still tender in the middle. Turn off the heat, slide the pan from the heat, and swirl it a few times to cool it slightly.
Drain the pasta, shake off the excess water, and slide the pasta and peas or favas into the pan of bacon; you'll hear a discreet sizzle. Place back on the burner (the one you used to cook the bacon, which should still be quite warm). Immediately pour the beaten eggs all over the steaming pasta, add most of the pecorino and lots of cracked black pepper and fold to combine.
Work quickly so the heat of the noodles, bacon and bacon fat slightly cooks the eggs. The eggs and ricotta will coat the pasta and form tiny, soft, golden curds.
Serve in warm bowls and offer the remaining pecorino and black pepper.
NOTE: If you prefer the egg cooked further, return the pan to low heat, but use a nonstick pan, or else much of the egg, and some of the pasta, will stick to the pan.Makes 4 Source: