Taiwanese stir fry vermicelli tshá bí hún

Name: Taiwanese stir-fry vermicelli (tshá bí-hún)
Ingredients: 320g thin rice vermicelli; 10g dried shrimp; 20g dried shiitake mushrooms; ½ sweetheart cabbage (about 100g), core removed, leaves roughly chopped; ½ celery stick (about 35g), cut into 1cm cubes; 150g beansprouts; 4 tbsp rapeseed or other vegetable oil; 150g pork belly, sliced into thin strips (or use streaky bacon); ½ large carrot, sliced into thin strips; 2 shallots, peeled and thinly sliced; 3 garlic cloves, crushed; 60ml light soy sauce; ½ tsp caster sugar; ½ tsp ground white pepper; small handful of chives, sliced into 2.5cm lengths; 1 tbsp crispy shallots, to garnish; Taiwanese black vinegar or Worchestershire sauce, to serve (optional)