Prepare the sauce for seasoning - Add the soya sauce, chilli sauce, sugar and vinegar to a bowl and set aside.
Rinse the fish and cut to cubes.
Add ¾ tsp soya sauce, 1 tsp ginger 1 tsp garlic paste, and ¼ tsp black pepper. Mix and set aside for 10 mins.
Heat a pan with oil for deep or shallow frying or preheat the oven and bake.
Add 1 ½ tbsps each of corn starch, all-purpose flour, salt to the fish. Sprinkle some water and mix to coat the fish with flour. The batter should not be runny. Fish has to be coated with a thin layer of batter.
Check if the oil is hot enough by dropping a small amount of batter. It has to rise without turning brown. Gently slide the fish pieces to the hot oil.
Fry them to golden on a medium flame. Drain these on a absorbent tissue.
After you finish frying fish, transfer the oil from the pan to a bowl retaining 2 tbsps in the same pan.
Making chilli fish manchurian
Add garlic and fry till it gets fragrant. Add capsicum, onions and fry on high flame for about 2 mins. Onions and capsicums should be crunchy (not over cooked) and not soft.
Stir in the sauces we made at step 1 and pour 2 tbsps water. Give a good stir and taste it. Add more sauces or salt if needed.
When the sauces begin to bubble, add the fried fish & give a stir. Stir fry on the highest flame for 2 mins. To make a gravy version, double the sauces and stir ¾ tsp corn flour with half cup water and pour it to the pan. Boil until thick then add the fried fish.