Peel the onions, cut in half and cut into thin slices. Rinse the schnitzel, pat dry, season with salt and pepper on both sides.
Heat the oil in a pan. Fry the schnitzel on each side for about 5 minutes, then remove from the pan and keep warm.
Sweat the onions in the frying fat for about 5 minutes (add a little water or white wine if necessary). Stir in the double cream, heat, season with salt and curry and spread over the schnitzel.
Serve the onion schnitzel with parsley or fried potatoes.