Season the fish fillet with salt and black pepper. Heat the sunflower oil and fry the fillets on both sides until golden brown. Cut the fillets into bite-sized pieces and season with cumin, turmeric, ginger and salt. In another pan, fry the onion slices. Add them to the fish and fill up with water while stirring. Now add the basmati rice to the fish pan and let everything cook for 40 minutes.