- In a small bowl, soak dried shrimps in warm water for 30 mins. Place yam cubes on a plate and steam over boiling water for 25 mins until softened. Remove and set aside.
- In a wok, heat up oil over medium high heat. Add dried shrimps and stir fry for 1 min then add in garlic and continue to stir fry until fragrant and shrimps have softened, about 2 mins. Add bok choy and stir fry until slightly wilted. Dish out and set aside.
- In the same wok, add yam, fish sauce, chicken stock and white pepper. Bring heat to medium low and let it simmer until the yam has become very soft and the gravy has reduced. The sauce should also turn out slightly thickened. Do a taste test and add another 1 tbsp of fish sauce if needed according to your taste. Stir well. Toss the bok choy, garlic and dried shrimps back into the wok and mix well for about 1-2 mins.
- Transfer to a serving plate and garnish with chopped red chillies if desired. Serve hot.