To make the filling, heat two tablespoons of oil in a wok, add onion and carrots and stir-fry for half a minute. Add green capsicum and cabbage and continue to stir-fry for one minute. Add soy sauce, white pepper powder and salt. Add bean sprouts and spring onions with the greens and stir-fry for about half a minute. Remove from heat and cool the filling to room temperature.
For Spring roll wrappers:
To make spring roll wrappers, mix one cup of cornflour, refined flour and salt to taste in a mixing bowl. Add two cups of water and whisk thoroughly. Strain the batter and set aside for fifteen minutes. Adjust the consistency of the batter by adding a little water if required.
Heat an eight-inch non-stick frying pan, brush with a little oil and pour a ladleful of batter into it. Swirl to coat the bottom of the pan and pour the excess batter back into the bowl. Cook over moderate heat till the edges start curling. Peel off or remove in one swift motion. Cool and sprinkle with a little cornflour.
Repeat the process to make eight to ten wrappers.
Mix one tablespoon of cornflour and two tablespoons of water to make a paste.
Divide filling into eight to ten equal portions. Place a portion of filling at one end of each wrapper and roll tightly, folding the sides in while you roll. Seal the ends with the cornflour paste.
Heat sufficient oil ( 100 ml ) in a wok, deep-fry two spring rolls at a time turning frequently, till crisp and golden brown. Drain and place on an absorbent paper. Cut each spring roll into four pieces and serve hot with Sichuan sauce / tomato sauce.