Combine the rice flour and tapioca starch in a bowl. Wash all the ingredients and place them in a food processor.

Mix the two flours together with 2 1/2 cups water (about 600 ml) and stir until smooth. Add 1 teaspoon salt and let the batter rest so it absorbs the water. Place the ground pork, wood ear mushrooms, shiitake mushrooms, and onion in a food processor and blend until fine. Add a pinch of salt, sugar, seasoning powder, and pepper, then mix well.

Heat a little oil in a pan and sauté minced garlic until fragrant. Add the pork mixture and stir-fry until cooked. Set up a steamer for making the rice rolls. When the water is boiling and producing enough steam, pour a thin layer of batter onto the cloth, cover, and steam for about 2 minutes until the rice sheet is cooked.

Gently remove the rice sheet, add the pork filling, and roll it up. Continue making rolls until all the batter and filling are used. Arrange the rolls on a plate, top with blanched bean sprouts, fresh herbs, thinly sliced cucumber, fried shallots, and slices of Vietnamese pork sausage. Serve with a bowl of sweet and savory dipping fish sauce.