Combine the flour and za’atar and spread out on a shallow plate. Fill a large high-sided pan with the oil to about 2 inches deep, then heat the oil to 190°C. Meanwhile, cut the halloumi into strips lengthways, approximately 1.5cm in width. Coat in the flour mixture, shaking off any excess.
Add the halloumi to the hot oil in batches. The temperature will drop when you add the cheese, so adjust where necessary. Fry for 3 minutes until golden, turning over occasionally. Remove and drain on kitchen paper and repeat until all the halloumi has been fried. Set aside and keep warm until ready to serve.