Wash and peel the asparagus and cook them, possibly steamed, for about 20 minutes. Meanwhile, sauté the chopped onion and 3-4 tablespoons oil in a large skillet. When the onion is golden, add half of the parsley and deglaze with the white wine. Add the shrimps, clean and without head, to the pan and cook over high heat for a few minutes. Meanwhile, cut the asparagus into about 2 cm pieces and keep aside 3 or 4 tips per person to decorate the dish. Blend the half of asparagus with the addition of a ladle of their cooking water to obtain a sauce of medium density. Add the sauce and asparagus pieces in the pan and cook for 2 o 3 minutes. Season with salt and pepper. Cook the pasta in boiling salted water. Drain the Fettuccine “al dente” and toss in the pan with the sauce. Add the remaining parsley, asparagus tips and serve. Bon Appetite!