Hot & sour soup
In a medium bowl, soak the mushrooms in warm water for 20 minutes, then drain, squeeze out any excess moisture and cut into 1cm/1⁄2in slices.
In a small dish, stir the cornflour into the sherry and set aside.
Put the pork loin in a large heavy pan and completely cover with water. Simmer until tender, then cool and shred.
Bring the stock to the boil. Stir in the pork, mushrooms and bamboo shoots. Simmer for 10 minutes, then stir in the soy sauce and red wine vinegar. Season with salt and pepper, then stir in the reserved cornflour mixture.
Keep stirring until the soup has thickened.
Remove from the heat and whisk in the egg. Mix in the tofu and heat through. Serve the soup hot.