Marinate the fish pieces with red chilli powder, black pepper powder and salt for 15 mins.
Soak dry red chillies in warm water for 5 mins and grind it into fine paste and keep aside.
Make batter by mixing together corn flour,refined flour,red chilli powder,black pepper powder,salt and sufficient water to make thick batter.
Heat oil for deep frying.
Dip the fish pieces in batter and drop into oil one by one,similarly fry all the pieces to golden brown and drain and keep aside.
Heat 2 tbsp oil in a wok,add gineger,garlic and green chillies. Toss for few seconds.
Add onions and salt and saute on high flame till onions turn translucent and crisp.
Add capsicum and saute till it becomes soft.
Add 1/2 tsp black pepper powder and mix.
Now add 1 tbsp Soya sauce and ground red chilli pastr and mix well
Add cornflour mixed water at this stage to adjust the consistency.
Add the fried fish pieces and mix well.
Finally sprinkle spring onion leaves and serve.