Cut the mushrooms into small pieces and soak in boiling water for 1 hour. Cut the bamboo shoots into thin slices; shredd or mince (grind) the ham. Bring the stock to the boil. Mince the chicken and pork, add to the stock and simmer for 10 minutes. Add drained mushrooms, bamboo shoots and ham, mix well and add the Msg and peas. Cut the top from the melon and scoop out the seeds and some of the pulp. Pour the soup into the melon and replace the top. Stand the melon in a basin and steam for about 1 1/2 hours or until the melon is cooked. The correct way to serve this soup is to place the melon on the table and scoop out soup and flesh, cutting the peel down as the level of soup is lowered.