Divide kidneys horizontally and cut out the strand of fat running down the middle with a sharp kitchen knife (*). Chop the kidneys and brown them briefly on all sides in clarified butter. Keep the meat warm.
In the same frying pan with a little clarified butter, fry the onions until golden brown, add the garlic and extinguish with jus and a little tap water. Boil the stock, then add red wine and thicken with a little cornflour or butter.
Pour in the chicken stock and boil thoroughly. Add parsley and kidneys to sauce. Heat briefly and serve.
Serve with fried potatoes.
(*) Leave fat on veal kidneys unless there is a lot of kidney fat. Be aware that veal kidney fat must be snow-white if the kidneys are fresh and not old.
Our tip: use your favorite red wine for cooking!