Make the filling: (a day ahead)

Cup of Yum
1. Heat up a wok with 1 tablespoon of oil and stir-fry the dried shrimps until fragrant.
2. Transfer to a bowl.
3. Add in the ground pork, soy sauce, black pepper, sugar and salt and saute until the pork is cooked.
4. Add in garlic and stir fry for another 2 minutes.
5. Next, add in the jicama, and dried shrimp (if using), and continue to cook until the jicama is slightly softened.
6. Add in carrots and leek, and cook for a few minutes.
7. Add in oyster sauce, taste and adjust the seasoning.
8. If the jicama contains a lot of water, add in 1-2 tablespoon of all-purpose flour to the mixture and cook for another 2 more minutes.
9. Transfer the cooked filling into a clean bowl and let cool completely.
10. Cover and chill in the fridge overnight.

Make the dough:

1. Combine wheat starch, rice flour, tapioca starch in a large heat-proof bowl. Give it a mix.
2. Pour in 600ml of hot boiling water into the flour mixture.
3. Mix with a wooden spoon, until the dough has cooled a little.
4. Knead the dough with your hands for 2-3 minutes.
5. Add in oil and continue to knead until the dough is smooth.
6. Cover the dough and let it rest at room temperature for about 10 minutes.
7. Form the dough into a long log and divide into 14g dough balls (for 3.25" diameter dumpling mold).
8. Flatten the dough by placing it in between a folded piece of parchment paper and pressing it between a tortilla press. (Thickness of dough should be ~1 mm).
9. Lightly grease the dumpling mold with sesame oil (only the first time) and place the dough in the mold.
10. Add 1 tablespoon of filling and close the mold firmly to form the dumpling.
11. Place the dumplings on a lightly greased steaming rack.
12. Repeat with the remainder.

Steam the dumplings:

1. Steam the dumplings on medium-high heat for 8 minutes, open the lid to let the steam escape, cover for another 2 minutes, or until the skin is translucent.
2. Remove the steamed dumplings and lightly brush with a little sesame oil while still hot.
3. Serve warm or at room temperature.