Dry-roast the sesame seeds in a frying pan over a low heat. Remove and leave to cool.
Mix the yeast in a bowl with a little warm water. Tip the flour into a large bowl, make a hollow in the centre and add in all the other ingredients except the oil. Knead the dough thoroughly, then roll out and cut into 10 x 8 cm (4 x 3½ inches) rectangles, 2.5 cm (1 inch) thick. Twist the rectangles and join the two ends.
Heat the oil in a deep-fat fryer or deep-sided frying pan and fry the cakes in batches until golden on all sides.
Meanwhile, heat the honey with the orange-flower water. Dip the hot halva in the glaze, then sprinkle with the sesame seeds.