In a small bowl, combine together ingredients for the sauce. Set aside.
Toss chicken pieces with cornstarch, soy sauce and dry sherry.
Heat 1 tablespoon oil and stir-fry chicken for 4 minutes or until no longer pink inside. Remove chicken and set aside.
Add remaining tablespoon oil to skillet. Add mushrooms and stir-fry, stirring until evenly browned, about 4 minutes.
Add asparagus and stir-fry, stirring for 1 minute.
Add chicken and sauce; stir and cook for 2 minutes or until sauce has thickened.
Serve over rice.