Take the required volume of water in a large bowl and add vinegar to it.
Soak fish pieces in it for at least 5 minutes.
Arrange fresh pieces on a flat surface and salt them to taste.
Season with red chili powder, black pepper, and crushed red chili. Optionally add the orange food color.
Add lemon juice and vinegar. Combine flour (maida), corn flour, and eggs to get the perfect crispy taste.
Keep aside for 15-20 minutes so that the fish gets marinated.
Coat with breadcrumbs before frying.
Heat oil and fry the fish fingers on low to medium flame.
You should get perfect crispy finger fish within 10 minutes of frying.