Mix all the sauce ingredients together in a small bowl.
Coat the raw chicken in cornstarch. Add half of the sauce to the chicken (leave remainder in bowl).
Add chicken and cook for 3 minute then remove and set aside.
In a pan, add onion, garlic, green onions, chilli and stems of broccolini. Sauté until tender.
Add the heads of broccolini, chicken, cashews.
Turn off the heat and add the remainder of the sauce. Mix throughly and serve with jasmine rice.