Cook the pancetta in a large skillet on medium heat until lightly golden and crisp. Set aside on paper towels to keep crisp, leaving the rendered fat in the skillet.
Bring a large covered pot of salted water to boil.
Meanwhile, add the chopped shallots to the skillet (and olive oil, if the skillet seems too dry), and cook on medium heat, stirring occasionally, until they start to color, about 5 minutes.
Add the peas, salt, and 1 cup of water, and cook covered until tender, stirring occasionally, around 20 minutes. Adjust for heat if needed.
Meanwhile, when the pasta water comes to a boil, add the pasta and cook, stirring occasionally, until al dente, tender yet still firm to the bite.
Transfer the pasta to the sauce with a slotted spoon along with 1/2 cup of the pasta water. Add the butter and toss over medium heat, until the water is almost absorbed, and the pasta becomes creamy.Turn off the heat, add the grated pecorino, pancetta and freshly ground pepper, and tossthoroughly.
Enjoy with more pecorino grated at the table. Buon appetito!
Substitutions
Dry-cured ham, such as prosciutto crudo or jamon serrano (diced or chopped from slices) can be substituted for the pancetta or bacon, and does not need to be pre-cooked. Add to the peas the last few minutes of cooking.
Guanciale - Pre-cook as directed for pancetta, or bacon.
Extras & Variations
Broth - For a little extra depth, add a ladle (or frozen broth cube) of chicken broth while cooking the peas.
Cream - Stir in a little while tossing the peas with the pasta over medium heat. (Around 4 Tablespoons per 2 servings)
Fresh Mint - Stir in at the end. Sprinkle on top to serve.