1. In a mixing bowl, combine flour, cornstarch, salt, and pepper. Add water gradually to make a smooth batter.
2. Dip cauliflower florets into the batter, ensuring they are well-coated.
3. Heat oil in a frying pan over medium heat. Fry the coated cauliflower until golden brown. Remove and set aside.
4. In the same pan, add a little more oil if needed. Sauté ginger garlic paste until fragrant.
5. Add sliced onions, bell peppers, and green chilies. Cook until they are slightly tender.
6. Add soy sauce, chili sauce, tomato ketchup, and vinegar. Mix well.
7. Add the fried cauliflower to the pan and toss to coat with the sauce.
8. Garnish with chopped spring onions and serve hot.