Originally a poor man’s dish, soupe de poisson à la rouille is a classic French soup and a close cousin of the famous bouillabaisse.
The soup is usually prepared with white fish that is cooked in a flavorful broth that mostly incorporates tomatoes, olive oil, garlic, saffron, and various herbs. The soup is then strained and served with rouille, a classic Provençal sauce that usually incorporates bread, garlic, spices, egg yolks, and olive oil while some versions can also include monkfish liver, tomatoes, or potatoes.