Step by step recipe:

1. 1 min.
   Cook the langoustines for 30 seconds (no longer) in salted boiling water.
   
   When cooled, shell them but do not discard the heads and claws.
2. 5 min.
   Prepare the langoustine stock:
   
   Prepare 1 shallot and chop finely.
   
   Prepare 1 carrot and chop.
3. 1 min.
   Pour 3 tablespoons olive oil into a saucean on medium heat. When hot, add the shallot, salt and pepper and cook for 1 minute without colouring.
4. 2 min.
   Add the carrot and parsley. Leave to cook for 2 minutes.
5. 1 min.
   Add the langoustine heads and claws.
6. 2 min.
   Crush these a little (I am using a rolling pin here) to bring out the flavour.
7. 1 min.
   Add 300 ml dry white wine and 200 ml water.
8. 40 min.
   Stir to mix well, then leave to simmer on low heat for 40 minutes.
9. 2 min.
   After this, strain the contents of the saucepan through a sieve and discard everything in the sieve.
10. 
    You will now have a very flavoursome langoustine stock.
    
    Note: this stage of the recipe can be prepared in advance and the stock kept in a sealed jar in the fridge or in the freezer.
11. 20 min.
    Prepare the sauce:
    
    Pour the stock into a small saucepan on low heat and reduce by half. There should only be 4 or 5 tablespoonsful of liquid left.
12. 5 min.
    Then add 200 ml liquid cream, mix well, turn the heat up slightly and bring to the boil.
    
    Add 1 knob butter and leave to reduce on low heat again until thickened.
    
    Check the seasoning and your sauce is ready.
13. 5 min.
    Prepare the sole turbans:
    
    Bring a saucepan of salted water to the boil.
    
    You can add a richer flavour to the dish by using fish stock, as in the photo, but this is not essential.
14. 2 min.
    Salt the sole fillets on both sides.
15. 4 min.
    Role into a hollow tube, like in the photo, and fix with two toothpicks so that they do not unroll during cooking.
16. 
    Prepare all the sole fillets like this.
17. 3 min.
    Lower the sole fillets into gently simmering water and poach for 2-3 minutes...
18. 
    ...then drain on a wire rack. Remove the toothpicks as this is easier while the fillets are still really hot.
19. 5 min.
    Pour 1 tablespoon olive oil into a frying pan on medium heat. When hot, sauté the langoustines until nicely browned.
    
    Heat the serving plates, particularly important for this recipe.
20. 
    Assemble the turbans:
    
    Arrange 2 turbans on each plate.
21. 5 min.
    Fill with sautéed langoustines and pour the sauce over or around.
    
    Garnish with, for example, a cherry tomato and a parsley leaf.
    
    Serve immediately.