Remove the shell from the shrimp and remove the intestines. Save the bowls for a small stock as needed.
Heat the olive oil in a heavy pan, add the garlic, but do not fry until brown and add the prawns. Season with salt and coarse pepper. Turn the prawns over. Then add the al dente cooked spaghetti.
Season with the zest of half a lemon and the juice of one lemon, mix in the chopped parsley and half a lemon, cut into thin slices.