Peel the cucumber and slice in half lengthways. Using aa teaspoon, remove the seeds and disard. Cut the cucumber into 3/4 inch slices and mix well with the 1 teaspoon of salt.
Allow cucumber to sit for about 20 minutes in a colander. This will draw out excess water. Rinse the cucumber in cold water to remove the salt and blot dry with paper towels.
Heat a wok or large skillet over high heat. Add the oil and when it starts smoking add the ginger and scallions. Stir fry for 30 seconds.
Add the cucumbers, black bean garlic sauce, salt, pepper and sugar. Stir fry for a further 30 seconds.
Add the 4 oz of water and stir fry for 3-4 minutes until most of the water has evaporated and the cucumbers are cooked. Add the sesame oil and serve immediately garnished with cilantro.