Take the pan off the heat, cut the feta into small cubes or crumble the feta into the mixture and combine with the borek filling.
3
Using 2 phyllo sheets at a time, brush each sheet with oil. Place the filling in a straight line along the long side of the sheet and then gently roll as you would when making a sushi roll.
4
Gently roll each borek into a swirl, place on a lined baking tray, mix the egg yolk with the oil to make a wash and brush each borek with the egg wash generously. This part is optional, sprinkle the sesame seeds on top and place in a preheated oven to bake for 30-40 on 190c electric fan until golden.