Step 1

Melt the butter and oil in a large saucepan. Add the onion and leek and cook over a low to medium heat until softened, about 5-10 minutes.

Step 2

Add the diced potato, bay leaf and a few grindings of freshly ground black pepper and cook for a few minutes.

Step 3

Pour in the milk and vegetable stock and place the fish fillets on top. Slowly bring the mixture to the boil, then turn the heat right down and cook for about 5 minutes. The fish is ready when it flakes very easily when touched with a fork.

Step 4

Remove the fish from the pan (it will be very tender by now and will break into pieces) and set aside on a plate, covering to keep it warm.

Step 5

Return the soup mixture to the boil, then turn the heat right down and simmer for about 10 minutes or until the potatoes are soft. Using a potato masher or fork, mash some of the potatoes into smaller pieces.

Step 6

Break the fish into chunks and return to the pan. Pour in the double cream and cook on a low heat for about 5 minutes. Season to taste, then pour the soup into serving bowls and sprinkle with freshly snipped chives or parsley.