Save several slices of cucumber for garnish, and leave the skin or part of the skin on this.
Peel the rest of the cucumber and cut into wafer thin slices, then dice if wished.
Cut the pork or chicken into tiny pieces.
Blend the cornflour with some of the cold stock.
Bring the rest of the stock to the boil, pour over the cornflour, return to the pan and cook until thickened.
Add cucumber, pork or chicken, soy sauce and salt and pepper.
Heat gently for about 5 minutes.
Add sherry, if used, just before serving, and garnish with cucumber slices.