Place the flour in a bowl. Pour the milk and water into another bowl. Combine the yeast and sugar, add to the liquid, add everything to the flour and mix well. Cover and leave to rise for approx. 15 mins. Separate the egg, add the egg white, half of the egg yolk (set aside the other half for brushing), the olive oil and salt to the dough, knead for 5-10 mins. Cover and leave to rise for a further 30 mins.
Divide the dough into 8 equal pieces. On a lightly floured surface, roll out the dough into round pita breads (each approx. 15 cm in diameter). Place on a baking tray lined with lightly oiled baking paper, leave to rise for a further 45 mins.
Combine the reserved egg yolk with the milk and salt, brush the pitas with the mixture, sprinkle with sesame seeds.
Bake for approx. 15 mins. in the centre of an oven preheated to 200°C.