01 - Combine ground pork, minced garlic, sugar, fish sauce, oyster sauce, cornstarch, black pepper, and oil in a large bowl. Mix thoroughly until the mixture becomes sticky and well combined.
02 - Wet hands with water and shape the pork mixture into 8 sausage-shaped logs. Preheat grill pan or grill over medium-high heat. Grill sausages for 10-12 minutes, turning occasionally, until golden brown and cooked through completely.
03 - Whisk fish sauce, lime juice, sugar, and water in a small bowl until sugar dissolves. Stir in minced garlic and sliced chili. Taste and adjust sweetness or acidity as needed.
04 - Rinse and thoroughly dry lettuce leaves, mint, and cilantro. Julienne cucumber and carrot into thin strips. Arrange all vegetables and herbs on a platter for easy assembly.
05 - Fill a large shallow dish with warm water. Dip one rice paper wrapper into water for 5-7 seconds until pliable but not soggy. Lay wrapper on a clean, damp towel.
06 - Place lettuce leaf on lower third of wrapper. Top with vermicelli, cucumber, carrot, mint, and cilantro. Add one grilled sausage. Fold sides inward, then roll tightly from bottom to enclose filling completely.
07 - Repeat assembly process with remaining ingredients to make 8 rolls. Serve immediately with prepared dipping sauce on the side.