In a bowl or a glass mix the water, yeast and sugar and let it sit for a couple of minutes until dissolved.
Meanwhile, combine the flour and salt in a large bowl and add the yeast water mix and olive oil.
Knead the dough for about 6-7 minutes until it is smooth and elastic.
Rub the dough and the bowl with oil and cover with a damp kitchen cloth. Let the dough rise for 30-40 minutes at room temperature or until doubled in size.
After rising, dust your work surface with flour and transfer the dough on your counter and divide into 10 equal balls (65g each).
First cover with a dry then damp cloth to prevent drying. Leave them for 30 minutes to rest
Using a floured rolling pin, roll one of the pieces into an ellipsis that’s 20-22 cm (7-8 inches) wide and about a quarter of an inch thick. Then let it sit for 3-4 minutes, for it to rise well while cooking.
Heat a cast iron pan and lay the rolled-out pitas directly on the hot pan. Instead of cast iron, you can use the back of an oven tray as well.
Cook the breads until they become partially brown for about 1,5 minutes on low heat. Then flip the pita over to cook for another 1,5 minutes on the other side. The pita is ready when it puffs up forming a pocket.
Remove from the pan and cover the pitas with a clean towel while you work on the rest of the pitas to keep them warm and soft.
To make the döner, mix all of the ingredients, except onion, in a bowl.
Sieve the onion juice on the mixture and knead until the mixture is homogenous.
Rest the mixture in the fridge for a day.
Wrap the mixture in a baking paper and squeeze from both ends to give it a log shape. Transfer to your freezer and let it freeze (You can keep it in the freezer for up to 6 months and use whenever you want.).
When it is time to cook, take out the frozen döner let it sit for 5 minutes.
Carefully, cut thin slices (as thin as you can). Don’t try to slice all the mixture at once, work in batches. You can prepare each portion at a time so you can cook the slices before they are thawed (you can deepfreeze the rest of the döner again for later. Don’t place it in the freezer if it is thawed).
Heat a large frying pan on medium heat and melt 1/2 tablespoon of butter.
Place the doner slices on the hot pan and cook both sides until they are browned. Don’t try to flip before one side is cooked.
Cook rest of the slices with the rest of the butter.