In a large skillet or wok, heat a tablespoon of vegetable oil over medium-high heat.
Add the minced garlic and cook until fragrant.
Add the ground pork and shrimp, and cook until they are no longer pink.
Add the shredded cabbage, carrots, and bean sprouts. Stir-fry for about 2-3 minutes until the vegetables start to soften.
Add the soy sauce, oyster sauce, sesame oil, and sugar. Mix well and cook for another 2 minutes.
Season with salt and pepper to taste.
Remove from heat and let the filling cool.
Lay a spring roll wrapper on a flat surface with one corner pointing towards you.
Place about 2 tablespoons of the filling near the corner closest to you.
Fold the corner over the filling, then fold in the sides and roll up tightly, sealing the edge with a little water.
Repeat with the remaining wrappers and filling.
In a deep pan or wok, heat enough vegetable oil to cover the spring rolls over medium-high heat.
Fry the spring rolls in batches until they are golden brown and crispy, about 3-4 minutes per batch.
Remove the spring rolls from the oil and drain on paper towels.
In a small bowl, mix together the soy sauce, rice vinegar, sugar, sesame oil, minced garlic, and chili flakes (if using).
Enjoy your meal!