01 - Combine ground pork, minced garlic, sugar, fish sauce, oyster sauce, cornstarch, black pepper, and 1 tbsp 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 outdoor grill over medium-high heat. Grill sausages for 10-12 minutes, turning occasionally, until golden brown and cooked through. Set aside to cool slightly.
03 - Whisk together fish sauce, lime juice, sugar, and water in a small bowl until completely dissolved. Stir in minced garlic and sliced chili. Adjust sweetness or acidity to personal preference.
04 - Rinse and thoroughly dry lettuce, mint, and cilantro. Julienne cucumber and carrot into thin, uniform strips.
05 - Fill a large shallow dish with warm water. Dip a rice paper wrapper into water for 5-7 seconds until just pliable. Lay wrapper on a clean, damp towel to prevent tearing.
06 - Place a lettuce leaf on the lower third of the wrapper. Add a small bundle of vermicelli, julienned cucumber, carrot, and a few mint and cilantro leaves. Position one grilled pork sausage on top. Fold both sides inward, then roll tightly from bottom to completely enclose the filling.
07 - Repeat assembly process with remaining ingredients to create 8 rolls total. Serve immediately accompanied by the prepared dipping sauce.