Remove the fenugreek coating from the pastourma and throw it away. Oil a 34cm baking pan and spread half the sheets in it, oiling them one by one. Sprinkle the kasseri, pastourma, graviera, oregano and the tomatoes on top. Lay the other half of the sheets, oiling them one by one, and press the perimeter with your fingers to seal them so the stuffing will not fall out. Oil, carve and slightly sprinkle water on the last sheet. Smear the surface with the beaten egg, open several holes in it with a fork and sprinkle with black sesame. Bake in a preheated oven at 180°C for 40 min, at the bottom rack.