Wash the potatoes thoroughly and cook in boiling water for about 20 minutes. Then drain, rinse and peel. Clean the mushrooms, wash if necessary and cut into slices. Heat 2 tablespoons of oil in a large pan. Sauté the mushrooms in it while turning.
In the meantime peel and finely dice the onions. Remove the mushrooms, add 1 tablespoon of oil to the pan and heat. Add the minced meat, crumble with a spatula and fry well while turning. Add the onions and fry. Stir in tomato paste, sweat it and season with salt, pepper, paprika and sugar. Deglaze with cream and stock, add mushrooms and simmer everything for about 5 minutes. Season again with salt, pepper, sugar and paprika. Wash thyme, shake dry, pluck leaves from the stalks. Cut the potatoes into slices, put them into an ovenproof dish, pulling up the edge. Fill the chopped mushroom cream in the middle.
Season again with salt, pepper, sugar and paprika. Wash thyme, shake dry, pluck leaves from the stalks. Cut the potatoes into slices, put them into an ovenproof dish, pulling up the edge. Fill the chopped mushroom cream in the middle. Cover with bacon slices, sprinkle with thyme leaves and cheese. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 30 minutes. Remove from the oven and garnish with oregano