Simmer the minced onions, potato slices (1 cm thick), and all other ingredients except the crabs for 1 hour. Before serving, remove the fish, and fill to cover the pot with boiling water and continue to boil. 5 minutes later add the crabs and fish, and boil for 5 more minutes. Delicately remove the potatoes and fish, and put them in an oblong plate. Filter the bouillon that you will serve in a tureen, the rouille in a sauceboat, and the bread slices in a plate.

Rouille: In a mortar crush the garlic and chillies, add a bit of bread soaked in milk and squeezed, the egg yolk and slowly add the olive oil. This sauce will be diluted with 2 tablespoons of fish broth. Each guest puts two slices of bread in his soup plate, then soup, and carefully add the rouille which is Hot, the potatoes anf fish can be added later or eaten at the same time.