Combine all purpose flour, rice flour, corn flour, chilli powder, soy sauce, salt, pepper and water in a bowl. Whisk to make a smooth batter.
Add baby corn and mix well. Use your hands to mix this to ensure the baby corn is evenly coated with batter
Heat oil in a deep pan or kadhai. Once hot, add the batter coated baby corn one by one. Fry for 5-6 minutes on a medium flame.
Combine soy sauce, vinegar, ketchup, red chilli sauce, corn flour and water in a bowl. Keep aside.
Heat oil in a wok or kadai till smoking hot. Add garlic, ginger and green chillies and saute till fragrant, about 30-40 seconds.
Add onion and capsicum and saute for 1 - 2 minutes. Remember to stir constantly.
Add the fried baby corn and toss to combine.
Add the sauce mix we made earlier on medium heat and stir continuously.
Add sugar, salt and pepper. Cook till the sauce thickens, about 1-2 minutes and becomes glossy.
Garnish with chopped coriander and serve hot!