Preheat the oven to 200 degrees top / bottom heat.
Cut the meat piece by piece with a sharp knife so that it becomes a kind of giant roulade or giant schnitzel. Salt, pepper and brush with the quark. Cover with ham and cheese, roll up and wrap with kitchen twine.
Brush the roll with oil and roll it in rosemary (of course, other herbs can also be used).
Heat the oil in a pan and fry the roast on all sides. Put the onions in the pan and fill the pan with enough stock to cover half of the roast.
Fry in the oven for about 1½ hours, dousing the broth over and over again.