Cut chicken into shreds, place in a mixing bowl with salt, pepper, sugar, cornflour, soya sauce and wine. Mix well together and set aside. Heat a wok or saute pan over fairly high heat. Lightly brown ginger in 1 tablespoon oil, add chicken and when colour changes, add mushrooms. Toss for several minutes, transfer to a bowl.
Heat remaining oil in the wok, add garlic and brown lightly.
Add snowpeas, stir-frying over high heat for several minutes, mix in water chestnuts. Stir in chicken and mushroom. A little water may be required to prevent sticking to the wok. Continue stirring until ingredients are heated through. If a sauce is desired add more water and when it is simmering, thicken slightly with cornflour dissolved in cold water.