Soupe de Poissons with Rouille and Croûtons

Soupe de Poissons is as much a provençal classic as its more famous cousin, bouillabaisse, but is less a fish stew than a fish soup or velouté. A traditional seafood dish on the French riviera, this silky smooth and delicious Soupe de Poissons features a traditional selection of fresh white fish used to make a rich broth that is infused with fragrant aromatics, chopped tomatoes, fresh orange zest and then puréed. 

This is the perfect dish to make when you’ve got some prawn or lobster shells, and wondering what to do with them, as they lend a wonderful intense flavour to the soup. You can find versions of Soupe de Poissons all along the Mediterranean coast, from Marseille to Menton, and pretty well everywhere else in between. It's lovely served from its own tureen, with the traditional toasted croûtons, grated Gruyère and sauce rouille on the side. It's always hot, spicy and satisfying, and makes an ideal precursor to a light main course of plainly grilled fish or seafood.

Soupe de Poissons with Rouille and Croûtons

Serves 4

For the rouille:

3 egg yolks

1/4 tsp of mustard

4 garlic cloves, chopped

1 tbsp of white wine

1 tsp of saffron

1/2 tsp of cayenne pepper

1 1/2 cups of olive oil

1 tbsp of lemon juice

salt

For the soup:

2 lb mixed fish such as cod, haddock, snapper or sole

1/3 cup olive oil 

5 tbsp each onion, celery and leek, chopped 

5 tbsp fennel, chopped plus fennel fronds for garnish

3 garlic cloves, sliced 

juice of orange, plus 2 strips of the zest 

3/4 cup tinned chopped tomatoes 

1 small red pepper, de-seeded and sliced 

1 bay leaf; sprig of thyme; pinch of saffron 

4 oz un-peeled, cooked prawns 

1 pinch of cayenne pepper 

4 cups good quality fish stock 

For the croûtons:

1 slim baguette, cut into 3/4-inch slices 

olive oil

3/4 cup freshly grated Gruyère cheese

For the rouille, place the egg yolks, mustard, and garlic in a food processor and blend all the ingredients for 30 seconds until it turns into a purée. Gradually add the olive oil to the puree while still blending, until you have a thick and smooth texture. When you have the desired consistency, place the saffron in the warm white wine and add to the mixture. Transfer the puree to a serving bowl and taste. Season with some salt and 1 tablespoon of lemon juice. Cover and set aside until needed.

For the soup, fillet the fish, removing any bones. Heat the oil in a large pan, add the vegetables and garlic and cook gently until soft but not coloured.

Add the orange zest, tomatoes, red pepper, bay leaf, thyme, saffron, prawns, cayenne pepper and fish. Cook for 2–3 minutes, then add the stock and orange juice, bring to the boil and simmer for 40 minutes.

To make the croûtons, heat the oven to 400°F. Cut the baguette in 3/4-inch thick slices and lay them in a single layer on a baking tray. Brush lightly with oil on one side and dry for 10 minutes in the oven until crisp but not hard.

Purée the soup in a blender then pass through a sieve into a clean bowl, pressing out as much liquid as possible. Return the soup to the heat and season to taste with the cayenne, salt and pepper.

To serve, ladle the soup into warmed bowls, spread rouille onto each croûton and float one on each portion of soup. Garnish with a fennel frond. Merveilleux!