Prepare the Filling: Cut the carrots, onion, and cabbage into julienne strips.
Cook the Vegetables: Heat oil in a pan, fry the onion, add cabbage, salt, and pepper, and simmer for 2 minutes.
Add Remaining Ingredients: Add carrots, bean sprouts, and soy sauce, and cook for another minute.
Cool the Filling: Remove from heat and let the filling cool.
Prepare Starch Glue: Mix 1 tablespoon of starch with 1 tablespoon of cold water, then add 50 ml of hot water until sticky.
Assemble the Rolls: Place a spoonful of filling on one corner of the spring roll sheet, roll halfway, brush sides with starch glue, and seal.
Fry the Rolls: Heat oil to 180°C and fry the rolls until golden brown. Drain on paper towels.