Humarsúpa (Icelandic langoustine soup)

Instructions

1. Shell the langoustines, keeping the shells, and set the flesh aside in the fridge.
2. Heat the oil and brown the shells for 5 minutes, crushing them with a wooden spoon.
3. Add the sliced onion and carrot, sauté for 3 minutes, then the chopped tomatoes and the tomato paste if using.
4. Sprinkle over the flour, stir, pour in the stock, bring to a boil and simmer for 20 minutes.
5. Pass the soup through a fine sieve, pressing the shells well, then return it to the heat.
6. Stir in the cream, the cognac and the langoustine flesh, let it simmer gently for 3 minutes and season before serving.