Sprinkle chicken with 2 teaspoons cornstarch, rice wine, and pepper. Mix well. Simmer mushrooms in chicken broth 5 minutes. Drain, reserving broth. Heat oil in a wok. Add chicken and cook, stirring, just until pieces separate and chicken is no longer pink. Drain into a sieve over a bowl. Return 1 tablespoon oil to the wok. Add mushrooms, bamboo shoots, and Chinese cabbage.Stir fry 2 minutes. Add chicken broth and sugar. Bring to a boil. Return chicken to the wok. Dissolve remaining cornstarch in water and add to the wok. Cook, stirring, until thickened.