Prepare the ingredients and simmer the shrimp and pork:
- Wipe the banana leaves clean and cut them into strips about 4.5 inches wide.
- Cut the pork and shrimp into small pieces, marinate with minced shallots and seasonings for 15 minutes, then simmer until cooked and the sauce thickens. Adjust the sweet and salty flavor to your taste. Turn off the heat and add scallions if you like.

Prepare the dough:
- Place the tapioca starch in a bowl and mix with 1/2 cup (120 ml) cold water until dissolved.
- In a pot, bring 1/2 cup (120 ml) water to a boil with 1/2 teaspoon salt and 1 tablespoon cooking oil. Once boiling, turn off the heat and quickly pour in the starch mixture, stirring rapidly until the dough thickens but does not fully cook.

Shape the cakes:
- Use a spoon to spread a little dough onto a banana leaf, add some shrimp and pork filling, then fold the two sides of the leaf over so the filling is enclosed in the dough. Roll up and fold the ends. After making two cakes, tie them together with a strip of banana leaf to make a pair.
- With these ingredients, you can make 8 pairs of cakes.

Steam the cakes:
When the water in the steamer is boiling, place the cakes in the steamer basket and steam for 20 minutes until cooked through.

Finished dish:
The dough is chewy and tender, and the shrimp and pork filling is flavorful and aromatic. Serve with a dipping sauce made from fish sauce and sliced chili for the best taste.