Cut the cucumber in half lengthwise and scoop out and discard the seeds then finely slice.

Mix the sugar, salt and rice vinegar in a bowl, add the cucumber and leave for 30 minutes, then drain and squeeze out excess moisture.

Whiz the pickled cucumber in a blender with olive oil until light and creamy, and chill until needed.

Roll each finger lime on a bench to loosen the vesicles, then cut in half cross-wise, and gently squeeze the little pearls out onto a teaspoon.

Add a drop or two of mirin to each oyster, then top with cucumber mixture and finger lime pearls and serve over ice.