Dissolve the yeast in warm water. Add the other ingredients and knead the dough. (You can prepare the dough in your bread machine.)
Set aside for 1 1/2 hours until the dough rises. During that time prepare the filling.
Cook the onion in olive oil until tender and add the spices.
Add the potatoes and stir until all got mixed for couple of minutes. You don't need the potatoes to be cooked thoroughly, just tender. Otherwise it will disappear while being cooked inside the pastry. Add chopped parsley after you turn the heat off.
Whisk egg and yogurt. Spread on the dough. Sprinkle sesame. Put it in a 400F oven until the surface gets golden