Wash and cut the cauliflower into small florets.
In a mixing bowl, combine all-purpose flour, cornstarch, ginger-garlic paste, red chili powder, salt, and enough water to form a smooth batter.
Dip each cauliflower floret into the batter, ensuring it is well-coated.
Heat oil in a frying pan or wok over medium heat. Once the oil is hot, carefully add the battered cauliflower florets in batches.
Fry the florets until they turn golden brown and crispy. Remove them using a slotted spoon and let them drain on a plate lined with paper towels.
In another pan, heat a small amount of oil over medium heat. Add the chopped spring onions and stir-fry for about 1 minute.
Add the soy sauce, tomato ketchup, green chili sauce, vinegar, and black pepper to the pan. Stir well to combine.
Add the fried cauliflower florets to the sauce and toss until well coated. Cook for an additional 2-3 minutes to heat through.
Serve hot as an appetizer or side dish.