Note Sour trahanas is available from Greek delicatessens.
Trahanas is a Greek pasta used in soups; it's made from semolina and bread flour. There are two varieties: the sweet one is made with milk as the binding agent, whereas the sour version, which we've used here, is made with yoghurt. It's quite sour and can be an acquired taste, so add the lemon juice incrementally to suit your palate. Try drying your own mint - hang a bunch to dry for three or four days. Its flavour is quite different from that of the shop-bought variety.