Open the cockles over a high heat with 2 tablespoons of water. Shake to ensure they all open, then pour into a sieve and collect their water which you will keep aside. When cooled, take the cockles out of their shells and wash them to remove all remaining sand. Sieve the cooking water, marinate the cockles in it to keep their flavor. This task, carried out quickly, has to be done if you wish to remove all the sand. Make a firm and very spicy mayonnaise. Serve sprinkled with very finely chopped chervil and parsley.
