01 - Prepare all vegetables by shredding cabbage, julienning carrots, slicing mushrooms and scallions. If using protein, cook and chop finely.
02 - Heat large skillet or wok over medium-high heat. Add 1 teaspoon vegetable oil, then sauté minced garlic and ginger until fragrant, about 30 seconds.
03 - Add cabbage, carrots, mushrooms, and scallions. Stir-fry for 2-3 minutes until just softened but still crisp.
04 - Add bean sprouts, soy sauce, sesame oil, oyster sauce if using, and white pepper. Stir-fry for 1-2 minutes more until well combined.
05 - Stir in optional protein if using. Transfer filling to a tray and let cool completely before wrapping.
06 - Place wrapper with corner facing you. Spoon 2 tablespoons filling near bottom corner. Fold bottom corner over filling, fold in sides, roll tightly, and seal edge with cornstarch slurry. Repeat with remaining wrappers.
07 - Heat 2 inches vegetable oil in deep pan to 350°F.
08 - Fry rolls in batches, turning occasionally, until golden and crisp, about 3-4 minutes. Drain on paper towels.
09 - Serve hot with sweet chili sauce, soy sauce, or your favorite dip.