Marinade: In a dish or bowl, blend cornflour with rice wine; stir in lemon juice, soy sauce, chillies, ginger and garlic. Blend and stir in chicken pieces to coat. Cover and refrigerate to marinate for 3 to 4 hours.
Stir Fry: In a wok or large frying pan, toast the sesame seeds over medium heat, shaking the pan until the seeds are a golden brown colour. Remove seeds and set aside.
To same wok or frying pan, add sesame oil and vegetable oil and heat slowly.
Drain chicken, reserving marinade, and stir fry in wok a few pieces at a time, until browned. Remove chicken with a slotted spoon and set aside.
Add mushrooms and green capscium to same wok or frying pan and stir fry for 2 to 3 minutes. Add the spring onions and stir fry 1 minute more.
Return chicken to pan, together with reserved marinade, and stir over medium high heat for another 2 to 4 minutes, or until the ingredients are evenly coated with the sauce. Sprinkle toasted sesame seeds on top and serve immediately.