Kitchen note: To achieve the glamourous effect of the salad in our photograph (above), let the gelatine chill in a bowl until the mixture just begins to congeal. How? Spoon a three-inch layer of the gelatine into the mold. Leave until partially congealed. Set cucumber slices into the gelatine, pushing them in to stand on end in a circle as in the photograph. Pour in almost all of the remaining gelatine and smooth with a spatula. Let chill or stand until set. Dip remaining cucumber slices one at a time into the leftover gelatine and arrange them in a single layer on top of the mold. Pour on remaining gelatine and smooth out. Chill at least two hours.
