Pasta with Asparagus-Lemon Sauce

Pasta with Asparagus-Lemon Sauce

1 pound fresh, medium thickness asparagus, tough ends trimmed
1 teaspoon finely grated fresh lemon zest
¼ cup extra virgin olive oil
1 pound penne or preferred pasta
½ cup grated Parmigiano-Reggiano Cheese

Cut asparagus into 1-inch pieces; reserve tips separately. Cook asparagus stems in 5 to 6 quarts boiling water with 2 tablespoons salt until very tender, 6 to 8 minutes.
Transfer with a slotted spoon to a colander, reserving cooking water in pot, and rinse under cold water. Drain asparagus well and transfer to a food processor or blender.

Cook asparagus tips in the same boiling water until just tender, 3 minutes. Transfer with slotted spoon to colander, reserving boiling water in pot, and rinse under cold water. Drain tips well.

Puree asparagus stems with zest, oil, and ½ cup asparagus cooking water. Transfer sauce to a 4-quart saucepan.

Cook pasta in boiling asparagus cooking water for about three-fourths of the recommended time (very el dente). You will finish cooking off the pasta in a sauce pan.
Reserve 2 cups cooking water and drain pasta.

Add pasta, asparagus tips, and ½ cup reserved water to asparagus sauce and cook over gigh heat, stirring, 3 to 5 minutes, or until pasta is almost al dente and sauce coasts pasta. Add more cooking water, a bit at a time, until sauce coats pasta but is a little loose (the cheese will thicken it slightly).

Stir in Parmigiano-Reggiano and salt and pepper, to taste and cook, stirring until cheese is melted. Serve immediately.