Cut the eggplants into slices and leave them to release their bitter juices. Fry the chopped onion and butter until golden brown. Add the meat, turn up the heat and sauté it, stirring constantly, until the meat changes color.
Add the peeled, cleaned of seeds and chopped tomatoes, wine, cinnamon and oregano, season with salt and pepper and leave over low heat for 45 minutes. Fry the eggplants in highly heated olive oil and then drain them from the oil. Spread olive oil on a baking tray and cover the bottom layer with eggplants, and thereon a layer of meat.
Repeat this process until you have run out of eggplants. Prepare 2 cups (500 ml) of béchamel sauce. Add 2 egg yolks and half of the grated feta cheese. Pour this mixture in the dish, sprinkle the top with the remaining cheese and bake until done.