Wash the turkey breast, pat dry and cut into 8 thick pieces/steaks. Peel onions and cut them into rings, except for one. Halve the bacon slices. Heat 1 tablespoon of oil in a pan.
Leave the bacon in it until crisp. Take it out. Put turkey steaks in the hot frying fat and fry briefly on both sides. Season with salt and pepper and take out. Put meat and bacon in an ovenproof dish.
Add 1-2 tablespoons of oil to the hot frying fat, heat up and fry the onion rings in it until golden brown. Stir in herbs of Provence and season with salt and pepper. Remove 1/3 of the onions from the pan.
Dust the remaining onions with flour in the pan, sauté briefly while stirring and deglaze with stock and cream. Bring sauce to the boil, simmer for 3-4 minutes and season with salt and pepper. Pour sauce over the meat and sprinkle with remaining onions and grated cheese.
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 30 minutes. In the meantime, clean the savoy cabbage, wash and cut into strips. Finely dice the remaining onion. Heat the fat in a pot and sauté the onion until transparent.
Add cabbage, braise briefly and season with salt, pepper and a little nutmeg. Add approx. 200 ml water, cover and stew for 15-20 minutes. Garnish turkey steaks au gratin with parsley and serve with savoy cabbage.
Boiled potatoes taste good with it.