Bring a small pot of salted water to a boil.

Chop the asparagus into small bits, removing and discarding the fibrous ends if needed. Blanch in the boiling water for about 5 minutes until slightly tender. Drain and rinse under cold water to stop cooking. Set aside the asparagus tips for decoration.

In a larger pot, bring salted water to a boil and cook the pasta according to package instructions, reserving about 1 cup of the cooking water.

Add the pistachios to a blender or food processor and blitz.

Add the cooked asparagus, garlic, lemon juice, parsley, olive oil, salt, and pepper to the blender. Puree until smooth, adjusting seasoning to taste.

Once the pasta is cooked, drain it and mix with the asparagus pesto. Add some reserved cooking water to achieve a silky texture. Plate the pasta, top with asparagus tips, sprinkle with lemon zest, and serve hot.