Soak dried shrimps in water for 10 minutes and roughly chop (reserve shrimp water for later use). Soak glass noodles in water for 10 minutes and drain well.
Heat up wok with some oil. Add garlic and dried shrimps, fry to aromatic. Throw in cabbage and carrot, stir fry for about 2 minutes. Add dried shrimp water, chicken stock and water, bring to boil. Cover and simmer at medium heat for about 15 minutes or vegetables softened.
Lastly add roast duck and glass noodles and simmer for another 10-15 minutes or glass noodles fully cooked through. Serve hot immediately.