A hearty fish soup

Ingredients to serve 4-5

500g raw prawns, unpeeled
About 15 mussels (optional)
800g in total of salmon fillet and any firm
white fish fillet
2 medium onions, chopped
3-4 garlic cloves, finely chopped
1 bulb of fennel, trimmed and thinly sliced
1 large carrot, peeled and sliced
5 medium potatoes, peeled and diced
5 medium tomatoes, cored and cut into large pieces
2-3 tablespoons olive oil
1 tablespoon butter
About 20 saffron threads
Half to 1 tablespoon ají (chilli in oil) or quarter teaspoon cayenne pepper
1-2 teaspoons dried thyme
2 sprigs of fresh rosemary, chopped
1.2 litres fish stock
200ml whipping cream
Juice of half a lemon, or to taste
A good pinch of sea salt
Freshly ground black pepper
Fresh flat-leaf parsley or thyme leaves

In a fish soup like this one, it's nice to use different kinds of fish: we often choose salmon and a firm white fish such as cod. And the fennel is a must, as it gives such a pleasant flavour to the soup.

To prepare the seafood, peel the prawns and wash the mussels carefully, if using. Cut the fish into 3cm cubes. Cover the seafood and set aside in the fridge. Peel and chop all the vegetables and set aside.

In a large saucepan or casserole dish, gently sauté the onion and garlic in the olive oil and butter. Flavour with the saffron, ají or cayenne pepper, thyme and rosemary. Stir to combine, then add the fennel, carrot, potatoes and tomatoes. Pour in the wine and stock and cook for about 30 minutes. You can prepare the recipe up to this point ahead of time if you like.

To finish, add the cream and bring the soup to the boil again. Season with lemon juice, salt and pepper. Add the fish and let simmer in the soup for 2-3 minutes. Carefully add the peeled prawns (do not allow to boil) and season to taste. Add the freshly cooked mussels, if using. Top with roughly chopped flat-leaf parsley or thyme leaves. Serve with bread, lemon wedges and ideally some extra ají.

Taken from: 'Under the Walnut Tree' by Anna and Fanny Bergenström (Hardie Grant, £20).