Dice the chicken breast into bite-sized pieces. In a bowl, combine the chicken with 2 tbsp soy sauce and cornflour. Mix well and set aside to marinate.
Prepare the vegetables: finely chop the ginger and garlic, slice the red pepper into strips, cut the broccoli into small florets, slice the carrot into thin rounds, and cut the spring onions into pieces.
Cook the basmati rice according to package instructions. Once cooked, keep warm.
Heat 1 tbsp vegetable oil in a large frying pan or wok over high heat. Add the marinated chicken and stir-fry until golden and cooked through, about 5-7 minutes. Remove from the pan and set aside.
In the same pan, add the remaining 1 tbsp vegetable oil. Add the ginger and garlic, stir-frying for 1 minute until fragrant.
Add the red pepper, broccoli, carrot, and mangetout to the pan. Stir-fry for 3-4 minutes until the vegetables are tender-crisp.
Return the chicken to the pan. Add the remaining 2 tbsp soy sauce, honey, and rice vinegar. Toss everything together and stir-fry for another 2 minutes.
Serve the stir fry over cooked basmati rice. Garnish with sliced spring onions and sesame seeds.
