1. Make the nuoc cham: In a small bowl, stir together the sugar, fish sauce, and 5 tablespoons water until the sugar is dissolved. Add the garlic, chilies, and lime juice. 2. Make the batter: In a bowl, mix together the rice flour, tapioca flour, and salt. Stir in 2 cups water and mix until the batter is thoroughly combined and smooth. 3. Make the filling: In a medium frying pan, heat the oil over medium heat. Add the shallot and wood ears and cook, stirring, until the shallot is soft, about 3 minutes. Mix the minced garlic and fish sauce into the pork and add it to the pan with the shallot. Season the meat with the fish sauce and salt and pepper to taste. Cook, stirring and breaking up the pork with a wooden spoon until the pork is browned, about 6 minutes. Transfer the filling to a bowl. 4. Set a medium nonstick frying pan over medium heat. Generously coat with oil and ladle in ¼ cup of the batter, swirling it around to coat evenly, about ⅛ inch thick. Cover with a lid and let the pancake cook for 1 minute. Carefully flip the pancake onto the plate. 5. Fill the pancake with 2 tablespoons of the filling down the center and roll up the noodle. Continue with the rest of the batter and filling. 6. Serve with nuoc cham and cucumber sticks.