Bouillabaisse is a classic French seafood soup, often served with a rouille - a Provencal mayonnaise-style sauce. This bouillabaisse recipe from Tom Aikens creates a dish which can be served in a number of ways, with the broth and fish plated separately, or in one steaming bowl - either way this is an incredible recipe, with a hint of aniseed flavour provided by the fennel.