Combine marinade ingredients and marinate duck for at least one hour.
Fry duck breasts skin side down in a hot pan for 10 minutes.
Turn the duck over and fry for an additional 5 minutes.
Remove pan from heat, pour marinade over duck, and rest in the pan.
Heat sesame oil in a separate pan and cook red peppers for 3 minutes.
Add chilli, ginger, and shallots and cook on high heat for 2 minutes.
Reduce heat, add sugar and lime juice, and cook until caramelised.
Add pineapple chunks and cook for 5 minutes.
Stir in the pak choi until cooked through.
Plate the vegetables, top with sliced duck, juices, and coriander stalks.