In a large bowl, combine the shredded cabbage, carrots, bell peppers, bean sprouts, green onions, and protein (if using). Add garlic, soy sauce, sesame oil, salt, and pepper, and toss until well mixed.

Take one spring roll wrapper and place it on a clean, dry surface or cutting board. Spoon about two tablespoons of the filling into the center of the wrapper. Fold the bottom of the wrapper up over the filling, tuck in the sides, and roll tightly to seal. Repeat with remaining wrappers and filling.

Heat vegetable oil in a large frying pan over medium-high heat. Once hot, carefully add the spring rolls (in batches if necessary) and fry until they are golden brown and crispy, about 3–4 minutes per side.

Remove the spring rolls from the pan and drain on paper towels to remove excess oil. Serve warm with your favorite dipping sauce, like sweet chili sauce or soy sauce!