In a large mixing bowl, combine shredded cabbage, shredded carrots, sliced bell pepper, sliced mushrooms, chopped green onions, minced garlic, grated ginger, soy sauce, sesame oil, and ground black pepper. Mix well until all ingredients are evenly incorporated.
Lay one spring roll wrapper flat on a clean surface with one corner pointing towards you (diamond shape).
Brush the edges of the wrapper lightly with vegetable oil using a pastry brush or your fingers.
Place about 2 tablespoons of the vegetable filling near the corner closest to you, forming a small line.
Fold the corner over the filling, then fold in the left and right corners towards the center.
Roll the wrapper tightly away from you until sealed. Repeat this process with the remaining wrappers and filling.
Preheat the air fryer to 375°F (190°C) for 3 minutes.
Lightly brush or spray the spring rolls with the remaining vegetable oil to help them crisp up.
Place the spring rolls in a single layer in the air fryer basket, making sure they do not touch. You may need to cook in batches.
Air fry for 10 to 12 minutes, turning the spring rolls halfway through cooking, until they are golden brown and crispy.
Remove the spring rolls from the air fryer and let them cool for 2 minutes before serving.