The day before peel and finely dice the onions. Wash the thyme, shake dry and scrape the leaves off the stems. Dab the cutlets dry, tap them a little flatter and cut each into 3-4 pieces.
Heat about 2 tablespoons of oil in a large frying pan. Fry the escalopes in it in portions on both sides for 2-3 minutes. Season with salt, pepper and some barbecue spices. Put the schnitzel on a plate.
Fry the onions in hot frying fat for about 10 minutes until light brown. Season with salt and pepper. Let cool off.
Alternatingly 1⁄3 Layer the escalopes and onions in a greased casserole dish, sprinkling each layer with thyme. Cover all ingredients with cream. Close the casserole dish with aluminium foil and chill overnight.
Remove aluminium foil the next day. Braise thyme cream meat in the preheated oven (electric cooker: 150 °C/circulating air: 125 °C/gas: see manufacturer) for approx. 2 hours. Cover if necessary so that the surface does not become too brown.
Baguette tastes good with it.