Preheat oven (electric cooker: 225 °C/circulating air: 200 °C/gas: level 4). Coat a baking tray with 2 tbsp. oil. Wash and clean the aubergine and cut lengthwise into slices of approx. 2 cm. Place on the baking tray and salt.
Bake in the oven for about 40 minutes until golden brown.
In the meantime, wash the potatoes and cook them in boiling water for about 20 minutes. Peel and chop onion and garlic. Wash oregano, shake dry, chop. Drain potatoes, rinse and peel.
Heat 1 tablespoon of oil in the frying fat. Fry the minced meat in it until crumbly. Add onion and garlic, fry briefly. Season with salt and pepper. Stir in chunky tomatoes and oregano, bring to the boil and simmer for about 5 minutes.
Season to taste with salt, pepper and cinnamon. Turn down the oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3).
Melt butter in a pot. Lightly sweat the flour in it while stirring. Deglaze with milk, bring to the boil and simmer for about 5 minutes. Season to taste with salt and pepper. Remove from the stove. First mix eggs and 4 tablespoons of sauce, then stir everything into the sauce.
Grate cheese. Wash the tomatoes. Cut tomatoes and potatoes into slices. First spread some sauce on the bottom of an oven dish, then layer potatoes and minced meat. Spread aubergines and tomatoes on top of it like roof tiles.
Pour the rest of the sauce over it and sprinkle cheese over it. Bake in a hot oven for 40-50 minutes.