Potato & pork soup
Put the chicken stock, potatoes and 1 tablespoon of the vinegar in a heavy saucepan and bring to the boil. Reduce the heat until the stock is just simmering.
Mix the cornflour with 4 tablespoons water to make a paste, then stir into the hot stock.
Bring the stock back to the boil, stirring until thickened, then reduce the heat until it is just simmering again.
Put the pork in a glass or ceramic dish, and season with the remaining vinegar, the soy sauce and the sesame oil.
Add the pork, carrot and ginger to the stock and cook for 10 minutes. Stir in the spring onions, pepper and bamboo shoots. Cook for a further 5 minutes. Pour into warm serving bowls and serve immediately.