Cut pork into bite size pieces. Peel carrots, cut into cubes. Place oil and garlic in wok. On high heat, brown pork. Stir-fry 5 minutes. Add plum sauce, celery, ginger, sherry, carrots, sugar, salt scallions and water. Simmer covered, 12 minutes. Add cornstarch to water and mixture to wok. Stir until thickened.