Wash broccoli and slice lengthwise so that the stems are thin.
To make sauce, combine soya sauce, water, ginger, garlic and sugar in a bowl. Set aside.
Heat oil in large skillet or wok. Stir-fry broccoli in oil for 3 minutes. Add sauce, stir well, put lid on pan and allow broccoli to steam for 3 to 5 minutes, or until tender.