Wash mussels. In a pan 3 tablespoon. Heat the olive oil. Add the mussels. Heat in a covered pan until the mussels open. Remove the clam meat with a sharp knife, keep the clam juice.
Heat the rest of the olive oil in a saucepan. Add crushed garlic cloves. Add the mussel juice and the meat. Let the whole thing boil down a little.
Add the peeled, finely chopped tomatoes, salt and pepper. Let cook for about 10 minutes. Stir in the parsley.
Mix the al dente, well-drained pasta with half of the sauce. Add the rest of the sauce.