Wash the loitta fish pieces and mix well with ginger, garlic and onion pastes, turmeric, red chili, coriander and cumin powders and salt. Also mix in the black pepper powder. Set aside for 1 hour.
Pour the biscuit crumbs in a tray and set aside.
Heat a pan with soybean oil.
Dip each fish piece in the beaten egg and roll on the tray with the biscuit crumbs.
Add this fish to the hot bubbling oil and deep fry until it turns slightly red.