Cut off a 4cm piece of ginger and grate. In a large bowl, mix 2 tablespoons of the soy sauce with the honey, orange juice and zest, grated ginger and five spice. Roll the pork in the sauce, coating well. Cover with clingfilm and place in the fridge to marinate for 1 hour.
Preheat the oven to 200°C, fan 180°C, gas 6. Heat a large frying pan over a medium-high heat and seal the pork on each side for 2 minutes, until brown. Transfer to a roasting tin; pour over the remaining marinade.
Roast the pork for 20 minutes, basting halfway through with the pan juices, until cooked through.
Meanwhile, cook the rice according to pack instructions. Shred the remaining piece of ginger. Heat the sesame oil in a wok (or clean frying pan), and add the remaining soy sauce, along with the shredded ginger, garlic, chilli and for 3-4 minutes until the pak choi stems are just tender.
Slice the pork and serve with the rice and pak choi, drizzling over any pan juices as a sauce.