Score the skin of the duck breasts in a criss cross pattern with a very sharp knife. Season the duck breast generously with salt and the five spice and rub into the skin thoroughly. Mix the honey and soy sauce in a bowl.
Place the duck breasts, skin-side down, on a dry ovenproof pan and cook over very low heat to render down most of the fat. This may take 10-15 minutes, depending on the thickness of the fat. Drain the fat from the pan.
Now turn up the heat and fry until the skin is crisp. Turn the duck breasts over and cook the other side for another 3-4 minutes. Just before the duck is ready, drizzle the honey and soy sauce over. Toss and turn the duck in the honey and soy and cook until the liquid has reduced to a syrupy glaze. Baste the duck continuously. Transfer the duck to a warm plate and leave to rest for 5-10 minutes.
Meanwhile, heat a wok or a large pan, add vegetable oil. When the oil becomes hot, add Pak Choi and oyster sauce. Stir fry it for 5 minutes, dish out onto a plate.
Slice the duck lengthways. You can use some of the Pak Choi as garnish.
I like serving it with plain rice, drizzled with any left over honey soy sauce.