Carve a cross on top of each tomato and scald it, i.e. place it in a saucepan with boiling water for 30 sec.
Immediately transfer the tomatoes in a bowl with cold water, to stop the boiling.
Peel and mince them.
Heat the oil in a low saucepan. Saute the onions for 4-5 min, until they become transparent but do not turn brown.
Add the minced tomatoes (without juices) and tomato paste.

Cook them over high heat for approx. 7 min, until completely dry. Add the balsamic vinegar cream.
Sprinkle with the flour and oregano, stirring. Lower the heat.
In a bowl, whisk the eggs and milk. Salt and pepper.
Pour over the stuffing, stirring.
Cook it over low heat, until the tomato cream thickens.
Leave the stuffing for the tomato pie to cool down for a few minutes.
Lay 3 pastry sheets creased on an oiled oblong 40×28 cm baking pan, oiling them in between. Make sure that the sheets reach well over the baking pan brim.
Pour half the filling on top, sprinkle with half the ground feta cheese and half the olives.
Cover the filling with one sheet, creased. Repeat with the remaining tomato cream, feta cheese and olives.
Fold the leaves spreading over the baking pan over the stuffing.
Cover the pie with the last 2 sheets, oiling them in between, slightly creased.
Slightly carve the pie only on the surface.
Sprinkle the surface with a little olive oil and water using your fingers.
Sprinkle with the sesame.
Bake the tomato pie in well preheated oven at 180°C, with extra heat on the top and bottom oven elements, placing the baking pan on the bottom rack. Bake for 40 min.