To make the dressing: whisk the Parmigiano Reggiano, olive oil, water, lemon juice and pepper (preferably freshly ground black pepper) together in a bowl.
Peel the fava beans, blanch the shelled favas in salted boiling water for 30 seconds, shock in ice water and drain. If the skin on the blanched favas is tough, double peel them by removing this second skin. You should only use the inner green favas for this recipe.
Wash the asparagus and snap off the woody bottom of each stalk. Cut the asparagus in bite-size pieces. Wash and sort the pea shoots. Toss the favas, asparagus and peas shoots with the dressing, arrange on 4 plates. Using a vegetable peeler, make shavings from the wedge of Parmigiano Reggiano. Garnish the plates with the shavings before serving.