Aromatic soy pork

Name: Aromatic soy pork
Ingredients: 150-175g/5-6oz pork tenderloin, depending on appetite; 150ml chicken stock; 2 tbsp soy sauce; 1 tbsp dry sherry; 1 tsp Chinese five-spice powder or 2 tsp 5-spice paste; 2.5cm/1in piece fresh root ginger, peeled and finely sliced; 1 garlic clove, peeled and finely sliced; half a bunch (about 4) spring onions, trimmed and left whole; about 50g flat rice noodles; 1 small bok choi or a few Chinese cabbage leaves; a drizzle of sesame or vegetable oil; 1 tsp toasted sesame seeds; a handful of coriander leaves