Pork and kimchi stew

Name: Pork and kimchi stew
Ingredients: 750g/1lb 10oz diced pork (shoulder or leg); 2 tbsp gochujang (Korean fermented chilli paste); 10g/⅓oz dried shiitake mushrooms; 1 tbsp vegetable oil; 1 large onion, thickly sliced; 1 large carrot, peeled and cut into chunks; 2 turnips or 1 small swede, peeled and cut into wedges; 200g/7oz kimchi; 1 tbsp soy sauce; 250ml/9fl oz chicken stock or water; bunch spring onions, roughly sliced (including the green parts); salt and freshly ground black pepper; steamed rice; small bunch coriander, leaves separated; 1 tsp sesame seeds; pinch gochugaru (Korean red chilli powder), or other chilli flakes