Bring a pot of water to the boil. Blanch rice noodles in this. Remove immediately and pour cold water over noodles. Drain.
Heat 2 tablespoons lard and lightly brown a quarter of the minced garlic. Add salt, then add chives and stir-fry till color deepens.
Add bean sprouts and continue stir-frying, 2 minutes. Remove and keep aside.
Add 2 tablespoons lard to pan and lightly brown remaining garlic. Add mushrooms, pork and prawns and stir-fry until meat changes color, about 2-3 minutes.
Pour in boiling water and bring to the boil. Return fried chives and bean sprouts to pan.
Thicken with cornstarch-paste. Remove and keep aside.
Heat remaining lard and fry well the rice noodles for several minutes, turning it frequently to prevent burning.
Dish up and top with cooked ingredients. Serve immediately.
