Cook the pasta in a large saucepan, al dente and drain it.
While the pasta is cooking, melt the butter in a large pan. Sauté the onion and garlic over medium heat until tender. Add shrimp and sauté on high temperature for 1 minute, stirring constantly. Stir in the liquid cream. Cook, stirring constantly, until the sauce thickens.
Put the pasta in a serving dish and pour over the shrimp sauce. Sprinkle with pepper and parmesan cheese. Decorate with parsley.