Pick out the spinach carefully, remove the hard midribs from larger spinach leaves. Rinse spinach thoroughly and place in a saucepan, dripping wet. Salt and steam over medium heat with lid closed until spinach leaves collapse. Drain on a colander.
Heat the butter in a bowl and sauté the onion cubes in it. Add the spinach, season with nutmeg and the juice of a lemon and toss the vegetables briefly. Stir in Parmesan cheese and whipped cream until smooth. Preheat the broiler.
Rinse the cutlets, rub dry and rub heartily with salt and pepper. Heat the oil in a coated frying pan and fry the escalopes in it over a high temperature for 2 minutes on each side. Place the fried cutlets one after the other on an ovenproof plate.
Spread a little spinach evenly on each cutlet and cover with the cheese cream. Place under the broiler or salamander and gratinate.
Tip: Did you know that one bowl of spinach provides about 50 percent of your magnesium needs?