I make mine pretty much like Islandgirl :D Have never had a complaint...You can omit the cheese if you prefer, for a lighter taste. I use the same recipe to cook myself some chicken or veal, since I can't have the shrimp. Whatever you do, do not overcook! Garlic can get bitter if it is overcooked, and shrimp gets tough.
Nice stainless stell pot, heat olive oil
heat slightly olive oil, add garlic (don't overcook), onions, parsley then add fresh shrimp, a little butter, then salt, pepper, and lemon squeezed, five minutes tops, then add parmesan or reggiano and voila done!
(hint! I add a little bit of Balsamic vinegar after parsley)
Make sure your pasta is al dente.