Heat sufficient oil in a kadai. Mix together cabbage, carrot, cauliflower, green chillies, garlic, ginger, salt, refined flour and 2 tsps soy sauce well. Shape into small balls, roll in cornflour and deep fry till golden and crisp. Meanwhile heat 1 tbsp oil in a non-stick pan. Add remaining ginger, garlic and green chillies, celery, remaining soy sauce and sauté. Dissolve cornflour in 2 tbsps water. Add vegetable stock to the pan and simmer for 1-2 minutes. Add cornflour mixture, pepper powder, vinegar and sugar and mix well. Drain the vegetable balls and add to the sauce. Mix well. Switch off the heat. Add half the spring onion greens and mix. Transfer into a serving dish and serve hot garnished with remaining spring onion greens.