Clean, wash and dry the spinach leaves. There should be no more water. Roughly cut the spinach leaves.
Fry the onion cubes and the garlic in a little oil. Stir in the cream cheese and crème fraîche and bring to the boil. Add the spinach leaves, mix well and cook for approx. 3 - 4 minutes while stirring. Season the spinach with a little salt and pepper and set aside.
Heat some oil in a pan. Season the turkey steaks a little and fry in them. They still need to be a little raw inside. Place the steaks in a pan for gratinating.
Stir the grated cheese into the spinach and spread over the turkey steaks. Bake the dish in the oven at 180 ° C top / bottom heat for about 15 minutes.
Carefully place a steak on each plate. Pour the gratin sauce around the steaks and serve the dish with boiled potatoes.