01 - Heat 1 tbsp vegetable oil in a large skillet or wok over medium-high heat. Add garlic and ginger, sauté for 30 seconds until fragrant.
02 - Add cabbage, carrots, mushrooms, and bell pepper. Stir-fry for 2–3 minutes until slightly softened.
03 - Add bean sprouts and green onions. Stir-fry for another minute.
04 - Stir in soy sauce, oyster sauce, sesame oil, and white pepper. Cook for 1–2 minutes until vegetables are tender but still crisp. Transfer filling to a colander and let cool completely, pressing gently to remove excess moisture.
05 - Place spring roll wrapper on clean surface with corner facing you. Add about 2 tbsp filling near bottom corner. Fold corner over filling, fold in sides, and roll tightly. Seal edge with flour-water paste. Repeat with remaining wrappers and filling.
06 - Heat about 2 inches vegetable oil in deep skillet or pot to 350°F. Fry spring rolls in batches for 3–4 minutes, turning occasionally, until golden brown and crisp.
07 - Drain on paper towels. Serve hot with sweet chili sauce or soy sauce.