Bring a large saucepan of water to the boil and add the salt and rice wine vinegar.

Reduce the heat so that it is just simmering and carefully break the eggs into the water, one at a time. Poach the eggs for 1 minute.

Remove the poached eggs with a slotted spoon and set aside.

Bring the chicken stock to the boil in a separate pan and add the leek, broccoli, chicken, mushrooms and sherry and season with chilli sauce to taste. Cook for 10-15 minutes.

Add the poached eggs to the soup and cook for a further 2 minutes. Carefully transfer the soup and poached eggs to 4 soup bowls. Dust with a little chilli powder and serve immediately.