Instructions: 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 same boiling water until just tender, 3 to 5 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 1/2 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 cooking time (very al dente). Reserve 2 cups cooking water and drain pasta.

Add pasta, asparagus tips, and 1/2 cup reserved water to asparagus sauce and cook over high heat, stirring, 3 to 5 minutes, or until pasta is almost al dente and sauce coats pasta. Add more cooking water, 1/4 cup 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.

This recipe yields 4 servings.

If you would like to email yourself the recipe for later use, or share the recipe with your friends or family, enter the email addresses below and this recipe will be emailed to you and others as well.