Boil pasta in salted water according to package directions, RESERVING 1 CUP OF THE PASTA BOILING WATER before draining.
In a small bowl, stir together the ricotta, salt, pepper, lemon zest and lemon juice. Set aside.
Melt the butter in a skillet over medium heat. Add about 2/3 of the green onion and cook, stirring, for about 1 minute. Add the ricotta mixture and stir to combine. Turn off heat until pasta is ready.
When pasta is cooked and drained, add to skillet with ricotta. Heat over medium heat, tossing, and adding some of the reserved pasta water as needed, to loosen the sauce, until warmed. Add prosciutto and parsley. Toss to combine.
Serve garnished with pea shoots, reserved green onion and a shaving of Parmesan cheese, if desired.
Be sure to read the “Ingredient and Cook's Notes" (above the recipe card!), where I share more detailedtips, variations and substitution suggestions for this recipe!