Pasta with Asparagus

Directions

Rinse the asparagus with cold water and using a peeler, remove the fibrous skin from the middle and downwards, preserving the tender tips. Bend the bottom part of each asparagus, and it will naturally break off. Keep the leftover pieces for making broth or other recipes.
Blanch the asparagus in boiling water for 2-3 minutes, then remove and set aside. In the same water, cook the pasta according to package instructions.
Trim the tips of all the asparagus, reserving 2-3 whole ones, and finely chop the remaining asparagus stalks. Make a puree by blending the chopped asparagus with a little water from the boiled asparagus.
Just before draining the pasta, add the asparagus tips and the finely chopped reserved asparagus to the pot. Drain the pasta, reserving some of the cooking water.
In a deep pan, melt the butter and saute the onion and garlic. Add the asparagus puree and the reserved water. Let it simmer and incorporate the sauce into the pasta. Stir well to combine, and just before serving, sprinkle with grated cheese and lemon zest.