1) Mix the hoisin with the ginger, garlic and 1 tbsp of the sesame oil. Rub into the lamb and leave to marinate for 1 hr.
2) Turn the grill to full heat, lay the lamb on a tray covered with lightly oiled foil and grill for 6 to 8 mins each side, taking care that it doesn't get too hot, as the hoisin may burn.
3) Meanwhile, bring a pot of salted water to the boil and cook the noodles, then drain and tip into a bowl. Pour on 2 tbsp of the sesame oil, then mix in the sesame seeds and keep warm.
4) Heat up a frying pan or wok (with lid) and add the remaining sesame oil, swizzle it around and then add the chilli and the pak choy (with the ends cut off to break the leaves up). Stir to coat with oil. Add the soy sauce and stir again, then place the lid on and count to 20.
5) To serve, place a pile of noodles on each plate, sit 2 pak choy on top then two of the chops. Scatter with the spring onions and eat.