Step 1

We prefer imported Prosciutto di Parma or domestically made prepackaged Volpi Traditional Prosciutto. If using slice-to-order prosciutto, ask for it to be sliced 1/16 inch thick. Look for a hard Gruyère that is aged for at least 10 months and use a rasp-style grater or the small holes of box grater to grate it. Tagliatelle is a long, flat, dry egg pasta that is about ¼ inch wide. If you cannot find tagliatelle, substitute pappardelle.

Step 2

Slice 2 1/2 ounces prosciutto crosswise into 1/4-inch-wide strips; set aside. Mince remaining 1/2 ounce prosciutto. Melt butter in 8-inch skillet over medium-low heat. Add shallot and 1/8 teaspoon salt and cook until softened, about 2 minutes. Stir in cream and minced prosciutto and bring to simmer. Cook, stirring occasionally, until cream mixture measures 1/2 cup, 3 to 4 minutes. Remove pan from heat and cover to keep warm.

Step 3

Meanwhile, bring 3 quarts water to boil in large saucepan. Add pasta and 1 1/2 teaspoons salt and cook, stirring often, until al dente. Reserve 1 cup cooking water, then drain pasta and return it to pot.

Step 4

Add 1/2 cup reserved cooking water, cream mixture, prosciutto strips, peas, Parmesan, Gruyère, and 1/2 teaspoon pepper to pasta. Gently toss until pasta is well coated. Transfer pasta to serving bowl and serve immediately, adjusting consistency with remaining reserved cooking water as needed.