Combine rice flour/starch with water and salt until well mixed.
Move the mixture to a pot and heat it at low flame. Keep stirring so the mixture won't stick to the pot.
Once the mixture thickens, add cooking oil.
Keep stirring until the mixture thickens into a batter. Then, turn the heat off and continue whisking to ensure the batter cooks evenly. Leave it aside.
Sauté shallots with cashew oil in a pan until fragrant.
Add ground pork and continue stirring.
Add ground shrimp once the pork is 80% cooked and continue stirring.
Season the pork-shrimp mixture with fish sauce, ground pepper, and sugar. Leave it aside.
Clean the banana leaves and pat them dry. Place one leaf on the table with its vein side down. Spread 1 spoon of the batter onto the leaf.
Place the filling on top of the batter. The ideal ratio is 2:1, with 2 parts batter and 1 part filling.
Fold both sides and both ends of the leaf to form a rectangle. Gently brush the leaf to distribute the dough evenly.
Repeat steps 9 to 11 until you use your batter and banana leaves.
Place the wrapped dumplings in a steamer. And steam for 15-20 minutes.
Serve your Banh Nam with Vietnamese dipping sauce (Nước Chấm). Sprinkle some spring onions and chili slices on top before eating.