Sure, here are four words that contain the letter "pasta" and are related to London:
Spaghetti: A long, thin type of pasta that is often served with tomato sauce or meatballs.
Pastaio: An Italian word for a pasta maker or pasta restaurant.
Pappardelle: A wide, flat type of pasta that is often served with meat or ragù sauces.
Pastificio: An Italian word for a pasta factory.