Cut chicken breast into thin slices. In a small bowl, mix chicken with soy sauce, cornstarch, and sherry, Set aside. Heat the oil in a wok over medium heat, add shallots and cook for about 1 minute. Add chicken and cook for about 4 minutes until it loses its pink color, then add chicken stock and allow to simmer. Add Snow Peas and cover wok for another 4 minutes, stirring occasionally. Remove cover and stir in ginger, and sugar. Cook for another 2 minutes. Mix well. Serve hot. Serve with white rice.