Prepare Nuoc Cham by whisking together fish sauce, sugar, rice wine vinegar, lime juice, minced garlic, and chili. Gradually stir in water and let sit for 10 minutes.

Soak the vermicelli noodles in a pot of hot water for 5-7 minutes until tender, then drain and rinse under cold water.

Mix pork mince, fish sauce, sugar, chopped green onions, minced garlic, white pepper, and optional lemongrass in a bowl. Form into small patties.

Cook meatballs in a skillet with heated oil for 2-2.5 minutes on each side until golden brown.

Assemble bowls with vermicelli noodles, meatballs, fresh vegetables, and a drizzle of Nuoc Cham sauce.