To make the cucumber and chive vinaigrette, peel the cucumber, removing all the green. With a vegetable peeler, make long slices of cucumber. Trim off the uneven edges, cut into long strips then finely dice these into tiny squares. Combine the olive oil and vinegar. Add 20 ml (½ fl oz) boiling water, stir together and season to taste. Just before dressing the oysters, add the snipped chives and diced cucumber and mix together thoroughly. Spoon the dressing over the oysters to serve.
To make the sauce mignonette, put the shallots and peppercorns in a container and top with the sherry vinegar. Mix together thoroughly and leave to infuse for at least 24 hours. Spoon over the oysters to serve.
To make the soy mirin pearls, blend the calcic with 500 ml (17 fl oz) cold water to make a calcic bath. Take 250 ml (9 fl oz) of the soy mirin stock, add the citras and blend briefly. Add the algin and blend again. Bring this mixture to the boil, then remove from the heat and allow to cool. Chill until cold, add the remaining stock, stir, then pass the mixture through a fine-mesh sieve. To create the pearls, you will need the syringe that is supplied with the calcic kit. Put the calcic bath into a deep gastronorm tray. Fill the syringe with the soy mirin stock and then drip droplets of the mixture into the calcic bath. The droplets will need 2 minutes in the calcic bath to set into pearls. Remove the pearls with a slotted spoon, then rinse under running water. Place on top of the oysters to serve.