Cut the chicken into 2.5cm/1in cubes and set aside.
Peel the cucumber, halve it and remove the seeds with a teaspoon. Then cut it into 2.5cm/1in cubes, sprinkle with salt and put the cucumber into a colander to drain for 20 minutes. (This removes the excess moisture from the cucumber).
Next rinse the cucumber cubes in running cold water and blot them dry with kitchen paper.
Heat a wok or large frying pan until very hot.
Add the oil and when it is very hot and slightly smoking, add the chicken cubes and stir-fry them for a few seconds.
Add all the other ingredients except the cucumber and continue to stir-fry for another 2 minutes.
Now add the cucumber cubes and keep stir-frying the entire mixture for another 3 minutes. Serve at once.