Combine glutinous rice flour, rice flour and salt in a mixing bowl. Pour in boiling hot water and mix with a pair of chopsticks. Leave aside for 2-3 minutes then knead into a smooth dough. Pinch off small pieces and roll into round balls.
Boil a deep saucepan of water. Drop in the balls of dough or tong yuen. When they start to float, remove and soak in cold water for 5-10 minutes.
In the meantime, bring chicken stock to a simmering boil. Add mushrooms, chicken fillet and dried shrimps. Cook for 7-8 minutes. Adjust seasoning to taste.