In a small bowl, combine white sugar, fish sauce, rice wine vinegar, lime juice, water, chopped chilis, and minced garlic. Stir until the sugar dissolves completely, and let it sit for about 10 minutes.

Bring a pot of water to a rolling boil and carefully add the vermicelli noodles. Follow the package instructions to soak them for 5-7 minutes, then drain well and rinse with cold water.

In a mixing bowl, combine pork mince, fish sauce, white sugar, chopped green onions, minced garlic, white pepper, and salt, plus optional lemongrass. Mix until well combined and form into meatballs.

Heat oil in a skillet over medium-high heat. Cook meatballs for 2-3 minutes on each side until golden brown and fully cooked.

Serve the meatballs over vermicelli noodles with fresh vegetables and drizzle with Nuoc Cham sauce.