Soupe de poissons with rouille

Step 1: Rinse 3 ⅓ lb mixed small whole Mediterranean fish (gurnard, weever, small whiting, rockfish) well under cold water, especially the cavities, and cut larger fish into chunks.

Step 2: Heat ¼ cup olive oil in a large heavy pot over a medium heat. Cook 2 onions, 1 leek and 1 fennel bulb for 10 minutes, until soft and starting to colour.

Step 3: Add 6 garlic cloves, 4 ripe tomatoes and 2 tbsp tomato purée and cook for 5 minutes, until the tomatoes collapse.

Step 4: Turn the heat to high, add the fish and stir for 8–10 minutes, crushing it with a wooden spoon, until the flesh is opaque, falls apart and starts to stick and colour on the bottom.

Step 5: Pour in 10 ½ cups water and add 1 pinch saffron threads, 1 tsp fennel seeds, 1 strip of orange peel, 1 bay leaf and 2 thyme sprigs. Boil steadily, uncovered, for 30 minutes. The rolling boil emulsifies the oil into the soup.

Step 6: Meanwhile, boil 1 floury potato in a ladle of the soup or salted water for 15 minutes until tender. Drain.

Step 7: Remove the bay, thyme and orange peel. Pass the soup through a food mill, then through a sieve, pressing hard on the solids. Don't blitz it with bones in a blender: that is the usual reason fish soup ends up gritty with tiny bone shards.

Step 8: Return the soup to the pot, season with salt and 1 pinch cayenne pepper and simmer for 5 minutes. It should be smooth and lightly thick, like single cream.

Step 9: For the rouille, pound 3 garlic cloves with ½ tsp dried red chilli or cayenne, 1 pinch saffron threads and a pinch of salt. Add the potato and squeezed-out 1 oz white bread, crusts removed and work to a paste, then beat in ½ cup olive oil in a thin stream until thick and glossy.

Step 10: Serve the hot soup with 1 baguette toasts (rubbed with garlic if you like), the rouille and 3 ½ oz gruyère or emmental: spread rouille on a crouton, top with cheese and float it on the soup.