Bouillabaisse is a traditional Provençal fish stew originating from the port city of Marseille. The French and English form bouillabaisse comes from the Provençal Occitan word bolhabaissa, a compound that consists of the two verbs bolhir (to boil) and abaissar (to reduce heat, i.e., simmer).

Bouillabaisse was originally a stew made by Marseille fishermen using the bony rockfish which they were unable to sell to restaurants or markets. There are at least three kinds of fish in a traditional bouillabaisse: typically red rascasse (Scorpaena scrofa); sea robin (fr: grondin); and European conger (fr: congre). It can also include gilt-head bream (fr: dorade); turbot; monkfish (fr: lotte or baudroie); mullet; or European hake (fr: merlan). It usually also includes shellfish and other seafood such as sea urchins (fr: oursins), mussels (fr: moules); velvet crabs (fr: étrilles); spider crab (fr: araignées de mer) or octopus. More expensive versions may add langoustine (European lobster), though this was not part of the traditional dish made by Marseille fishermen. Vegetables such as leeks, onions, tomatoes, celery, and potatoes are simmered together with the broth and served with the fish. The broth is traditionally served with a rouille, a mayonnaise made of olive oil, garlic, saffron, and cayenne pepper on grilled slices of bread.

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