Dry the calf’s liver with household paper, remove the skin and tubes and cut into very fine strips (shred). Remove the skin from the onions and cut them into thin rings. Heat half of the lard in a large, deep frying pan and fry the onions in it until golden. Then move them a little to the side.
Heat the remaining lard in the frying pan and roast the liver strips in it, stirring, for 2-3 min. Dust with flour, sweat lightly and extinguish with white wine and whipping cream. Stew gently for 5 min, stirring frequently. Next season with sugar, pepper, salt and wine vinegar if desired.
Arrange the liver in a heated baking dish and bring to the table sprinkled with lemon zest and parsley.
If the liver is served as an entrée, it is accompanied by fresh white bread. For the main course, serve with rump, roast potatoes or mashed potatoes and lettuce, and dry white wine as a beverage.