2) Add the chicken and cook for 4-5 minutes or until lightly browned. Add broccoli, mushrooms, carrots, pepper and onion and cook an additional 5 minutes, stirring frequently. Stir in the water chestnuts.
3) In a small bowl, combine stock, hoisin sauce, soy sauce, ginger and cornflour.
4) Add sauce to chicken mixture and bring to a boil over medium-high heat.
5) Reduce heat to medium to medium-low, and simmer for 4-5 minutes, or until sauce thickens. Serve over hot, cooked rice noodles.