Combine together all-purpose flour, corn starch, red chili powder, garlic powder, salt and a little bit of water to form a batter thick enough to coat each cauliflower floret.
Heat the oil in a pan and deep fry the cauliflower florets coated with batter, till golden brown and crisp. Set aside.
Heat 2 tablespoons of oil in a large non-stick pan. Add in garlic and ginger, and fry for a few seconds till fragrant. Add in the onions and fry for a few minutes till lightly browned.
Stir in white pepper, coriander powder, tomato-chilli sauce and soy sauce, and let it come to a simmer to form a thick saucy consistency. Season with salt if needed.
Toss in the fried cauliflower florets, and mix with the sauce to coat well.
Garnish with chopped spring onions and serve immediately.