Heat a small pan with the sesame oil. Add
ginger, onion, garlic and scallions. Cook over moderate heat for 3
minutes or until onion is soft and golden. Stir in the soy sauce, sugar,
fish sauce and water. Set aside while preparing and cooking the fish. Mix the flour, cumin, coriander and paprika in a medium-sized bowl. Cut the fish fillets into 2 cm cubes. Dip the cubes in the egg whites and dust lightly with the spiced
flour, shaking off any excess. Heat the oil in a deep pan or wok, add the fish pieces in batches
and deep-fry over high heat for 3 minutes or until golden and cooked
through. Drain on paper towels and keep warm. Dissolve the cornstarch in the water, add it to the sauce mixture,
stirring constantly until the mixture boils and thickens. Serve the fried fish pieces topped with the hot sauce.
Garnish with sliced scallions.