Ingredients
Kosher salt
1-1/2 oz. prosciutto rind
2 cups lower-salt chicken broth
1/4 cup extra-virgin olive oil
1 oz. (2 Tbs.) unsalted butter
1 medium leek, dark-green top removed, light part halved lengthwise, cleaned, and thinly sliced (1 cup)
6 medium scallions, trimmed and thinly sliced (1 cup)
Freshly ground black pepper
1 lb. fresh pappardelle pasta
1 cup English peas, fresh or frozen
1 oz. finely grated Parmigiano-Reggiano (1 cup using a rasp grater); more for serving
1/4 cup chopped fresh flat-leaf parsley
Preparation
Bring a large pot of well-salted water to a boil.
Combine the prosciutto rind and chicken broth in a 3-quart saucepan and bring to a boil. Reduce to a simmer, cover, and cook for 10 minutes to infuse the broth. Let the rind steep until ready to use the broth.
Meanwhile, in a 12-inch skillet heat the olive oil and 1 Tbs. of the butter over medium heat until the foaming subsides. Add the leek and scallions, season with 1/2 tsp. salt and 1/4 tsp. pepper, and cook, stirring often, until softened, about 8 minutes.
Add the pasta to boiling water and cook, stirring occasionally, until 1 minute under al dente.
Remove the prosciutto rind and add the broth to the skillet with the leeks and scallions. Bring to a boil and reduce by half, about 7 minutes. Stir in the peas and the remaining 1 Tbs. butter.
Using tongs, carefully transfer the pasta to the skillet, reserving the pasta water. Add the Parmigiano and parsley and toss well to combine. Season to taste with salt and pepper, adding some pasta water to loosen if necessary. Serve immediately with additional cheese.
