Heat oil in a frying pan over medium heat. Add garlic, onion, wombok, carrot and mushroom. Cook, stirring, for 5 to 6 minutes or until cabbage has wilted.
Remove from heat. Stir in bamboo shoots and soy sauce. Cool for 10 minutes.
Place wrappers on a flat surface. Spoon 2 teaspoons cabbage mixture on 1 half of each wrapper. Brush edges with cold water. Fold over to enclose filling.
Press edges together to seal. Place on a tray lined with baking paper.
Place a steamer lined with baking paper over simmering water. Cook dumplings, in batches, for 15 minutes or until tender and cooked through. Serve.