Pour the flour into a mixing bowl, make a well in the center, and add the egg, oil, water, salt, and vinegar.
Combine the ingredients in the well and slowly draw in the flour, mixing with your fingers until a dough starts to form.
Form the dough into a ball and turn out onto a floured work surface. Knead the dough until you achieve a soft, elastic dough which is no longer sticky.
Put the dough back in the bowl and cover with a damp tea towel and rest on the sideboard for 30 minutes. Alternatively, flour the ball a little and drop it into a plastic freezer bag, give it a twist to get rid of the air, and leave it to rest for 30 minutes.
While the dough is resting, preheat the oven to about 200-210 °C (392 - 410 ℉) (medium heat).
Now it’s time to start making the cheese filling. You should use about 500 g (1 lb) of cheese, but you can add more if you like a thicker layer of cheese in your pie (or indeed less, if you like it less cheesy).You can use different types of cheeses for this pie, from fresh cow's cheese to fresh or semi-aged sheep's milk cheese. You can also use Feta, goat cheese, Neuchâtel, paneer, or queso fresco. Combine the cheeses well, and break up the harder ones with a fork, then add sour cream and eggs, little by little, until you reach a nice sloppy consistency. I recommend adding the eggs/cream gradually: the amount you need will depend on the initial consistency of the cheese and the size of the eggs so make adjustments where needed. The consistency you want is quite thick, certainly not ‘pourable’, but something like a thick cake batter or bricklaying mortar (if that helps you at all!). Taste it when you’ve done combining it and add salt if necessary. You’ll need to brush the sheets of dough with a little butter or oil. If you intend to use butter, now is the time to melt it in a pan over a very low heat.
Once the dough is sufficiently rested, it’s time to roll it out.Butter or oil the bottom of the baking tray well. Then on a clean and well oiled surface, divide the dough into 4. Spread out each piece of dough using your hands or a rolling pin until very thin but not too fragile. Spread a quarter of the cheese filling, and roll up the dough into a long sausage-like shape. Form a spiral around one end of the dough roll and carefully place into a pan. Continue with the rest of the dough and filling, adding each cheese-filled dough roll to the spiral in the baking pan. You can skip rolling altogether, and stack the sheets on top of one another. For this you'll need to first of all, roll the dough into a sausage and cut into six equal parts. Form each sixth into a ball and then roll it out until it is the size and shape of the baking tray you intend to use (mine was a 25 cm/ 10-inch diameter circular tray, about 3 cm / 1 ½ inches deep). Place in the first sheet of dough in the oiled baking pan. Brush it with butter/oil, then put in the second sheet, then half the cheese, spreading it out to about 1 cm (½ inch) from the edge of the tray. Then add another two sheets of dough (the first, again, brushed with butter/oil). Now add the rest of the cheese, again spreading it out until it’s about 1 cm (½ inch) shy of the edge of the tray. Finally, add the last two sheets of dough, brush each with butter/oil. Once you have the pie in the pan, gently run the back of a knife over the top to mark the portions, dividing it into eight wedges (you could use a circular tray). You don’t need to cut through the dough, just depress it so that the cutting point will be more clearly defined at the end of the baking process. Now, put the pie into the preheated oven and cook for about 20-30 minutes until the top has started to brown. At this point, make a mixture of one egg and three tablespoons of sour cream or yogurt, according to preference. Spread this mixture over the top of the pie and return it to the oven for another 15-20 minutes, or until once again brown. An egg beaten with 1-2 tablespoon of sour cream/yoghurt will help make the pie crust moist but still appealing and the sesame seeds work fine with the cheese. Once it’s nice and brown all over (but not burnt!) take it out of the oven, let it cool down for a few minutes, and then cut into portions using the lines you scored in it earlier.
For the apple filling, start with grated apples, sautéed in a frying pan with some butter, sugar, and a cinnamon stick. The apples are ready when the apple juice is all evaporated; the point here is not to have any apple juice pouring around in the baking tray. Proceed with baking just as with the cheese version.