2 tbsp Chinese black rice vinegar, cider or white wine vinegar
1 thumb-sized piece ginger, finely sliced into matchsticks
½ red chilli, sliced
½ pack silken tofu, diced
handful frozen sweetcorn
150g cooked prawns
2 eggs, beaten with 1 tsp sesame oil
150g beansprouts, rinsed
shredded spring onions, to serve
Put the stock in a saucepan over a low heat, add the sugar, vinegar, ginger and chilli, and bring to a gentle simmer. Add the tofu, sweetcorn and prawns, simmer gently for 2 mins, then pour in the egg mixture in a steady stream, stirring to make egg strands.
Pile some beansprouts in each bowl and ladle the soup over. Scatter over the spring onions and serve.