Cut the fish into bite-sized pieces.

In a bowl, mix maida, corn flour, baking powder, soy sauce, pepper, and salt.

Add water to create a smooth batter.

Dip the fish pieces into the batter.

Heat oil in a pan or wok for deep frying.

Fry the fish pieces until golden brown and crispy. Remove and set aside.

For the sauce, heat some oil in a separate pan or wok.

Add chopped ginger, garlic, and green chili. Saute for a minute.

Add soy sauce, tomato sauce, and chili sauce.

Mix corn flour with a little water to create a slurry.

Add the corn flour slurry to the sauce and stir until it thickens.

Add the fried fish pieces to the sauce and toss to coat.

Add finely chopped celery and mix well.

Garnish with spring onions and serve hot.