Ingredients
Coarse salt and ground pepper
12 ounces spaghetti
4 tablespoons butter
2 medium leeks (6 to 8 ounces each), white and light-green parts only, halved lengthwise and cut into 2-inch pieces, well rinsed
1 package (10 ounces) frozen peas
2 tablespoons fresh lemon juice
2 ounces (about 1/4 cup) thinly sliced prosciutto cut into thin strips
2 ounces (about 1/3 cup) ricotta salata or Parmesan cheese shaved with a vegetable peeler
Preparation
In a large pot of boiling salted water, cook pasta until al dente, according to package instructions. Reserve 1/2 cup pasta water; drain pasta, and return to pot.
While pasta is cooking, heat 1 tablespoon butter in a large skillet over medium. Add leeks; season with salt and pepper. Cook, stirring occasionally, until tender, 3 to 5 minutes. Add peas; cook, stirring, until warmed through, 2 to 3 minutes.
To drained pasta, add leek mixture, remaining 3 tablespoons butter, lemon juice, and prosciutto; season with salt and pepper. Add reserved pasta water a little at a time, tossing, until a thin sauce coats pasta. (You may not need all the water.) Serve, sprinkled with ricotta salata.
