Crush or finely chop the garlic. Cut the onion into thin wedges. Coarsely chop the capsicum. Cut the leaves from the pak choy, quarter the stems lengthwise, then thickly slice.
Step 2 — Prep chicken
CHICKEN STIR-FRY OPTION Combine the garlic, Chinese barbecue seasoning and 2 tsp oil in a large bowl. Thinly slice the chicken into strips, add to the seasoning mixture and stir to coat.
Step 3 — Stir-fry chicken
Heat 2 tsp oil in a medium deep frypan over high heat until hot. Stir-fry the chicken for 2-3 mins until cooked through. Remove from the pan.
Step 4 — Cook vegetables
Heat 2 tsp oil in the frypan over medium-high heat. Cook the onion and capsicum, stirring regularly, for 3-4 mins until starting to soften.
Step 5 — Prep and add sauce
Meanwhile, combine 1½ tbs sweet chilli sauce*, 1 tbs oyster sauce* and 2 tsp soy sauce in a bowl. Add the pak choy stems and sauce mixture to the onion and capsicum. Increase the heat to high and cook, stirring, for a further 1-2 mins until the pak choy is just tender.
Step 6 — Finish stir-fry and serve
Add the chicken and pak choy leaves to the vegetables and stir-fry for 1 min or until the leaves are wilted. Divide the chicken stir-fry among bowls and scatter with the sesame seeds to serve.