Mix an equal amount of labneh cheese, curd cheese, and feta cheese with an appropriate amount of yellow bell peppers and onions that have been roasted in vegetable oil. Mix the filling until incorporated. Add as much of the filling as you wish inside of the mille feuilles. Either fold the pastry and press the knife into the pastry to make a shallow slit or use the millefeuille in the shape of a square. Add egg yolk on top of your Pek Mille-Feuilles. Preheat oven to 190C, and bake for around 15-17 minutes.