Score each chicken breast several times with a knife and put one on each of 4 x 30 cm (12 inch) squares of foil.
Combine the soy sauce, honey, garlic, chillies, ginger and star anise in a small bowl, then spoon over the chicken.
Arrange 3 pak choi quarters on top of the chicken breasts. Seal the edges of the foil together to form parcels, transfer to a baking sheet and bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 15 minutes until the chicken is cooked through.
Leave to rest for 5 minutes, then serve the parcels with boiled jasmine rice.