Place cauliflower florets in hot salted water and let sit on medium heat for 3-4 minutes to soften.
Cool down and drain.
Make batter by combining dry ingredients and slowly adding water to avoid lumps.
Heat veg oil in a wok or small pot on medium heat.
Dip cauliflower in the batter and fry in batches for 3-4 minutes and drain.
When all fried, increase the heat to high and fry again in batches for 1-2 minutes until golden brown and crispy.
To make the sauce, heat 3 tablespoons oil in a wok or pan and add onions and fry for 3 minutes on medium heat. Add garlic, ginger and green chilli and fry for another 2 minutes.
Add soy sauce, ketchup, vinegar, hot sauce and red chilli paste and cook for 1 minute.
Add water and bring to boil.
Add cornstarch and mix and boil for 3-4 minutes until thickened.
Turn down the heat, add cauliflowers and mix until all florets are coated in the sauce.
Check seasoning and add garnish.
Serve while hot.