Rinse the sticky rice well and let soak in water for at least 3 hours.
Beat egg in a large bowl. Mix in salt, ginger and soy sauce. Add minced pork, cornflour and stock. Stir well in one direction until combined for about 5-6 minutes.
Boil enough water for steaming in a wok or a pot.
Meanwhile, drain the sticky rice and set aside. Roll the meat mixture into bite-size small balls. Roll the balls in the sticky rice until they are coated completely with rice. Place 6 balls in the steamer.
Place the steamer into the wok and steam for about 30 minutes. Turn off the heat. Remove the balls, garnish with wolfberries and serve.