Wash potatoes thoroughly and cook in boiling water for about 20 minutes. Then drain, rinse and peel. Cut potatoes into slices. Meanwhile clean and wash the cauliflower, cut off the florets and cook in boiling salted water for 12-14 minutes.
Pour into a sieve and drain well. Peel onions and garlic and dice finely. Wash the meat, dab dry and cut into fine cubes. Heat the oil in a pan and fry the meat thoroughly, turning it over.
Add the onion, garlic and marjoram and fry briefly. Season with salt and pepper. Mix in tomato paste, add tomatoes and stock and let simmer for about 10 minutes. Season again with salt, pepper, paprika and sugar.
Place the potato slices in a greased ovenproof dish. Spread cauliflower florets around the edge. Place turkey bolognese in the middle and sprinkle with cheese. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 25 minutes.
Garnish with marjoram.