This recipe is from Chef-patron David Wilson of the Peat Inn, Fife. By preference he would have roe deer liver which has a mild delicate flavour - much appreciated in central Europe. The liver of the red deer has a stronger flavour but can be used in the same way. [A Scottish stalker told me to slice up red deer liver and then soak it overnight in milk to reduce the strong flavour]

    Sauté 2 tablespoons of onion in a very little oil until soft, add the sugar, red wine and vinegar. Reduce until almost evaporated, then add the stock.  Simmer gently to concentrate the flavour and reduce slightly.  Set aside.  The sauce can be prepared up to this point several hours ahead.

    Cook the potato and second 2 tablespoons of onion in oil until they are crisp and golden.  Drain on kitchen paper and keep warm (this too can be done in advance and re-heated before serving).

    At the last moment before serving season the liver with salt and pepper. Heat the oil in a sauté pan and cook the slices briefly on each side. They should be nicely browned on the outside but kept rosy inside. Drain on kitchen paper and keep warm for a few minutes while you finish the sauce. Re-heat the sauce then whisk in the cubed butter, on and off the heat, to thicken the sauce.  Season to taste.

    Spoon some sauce on to heated plates.  Place the liver slices on the sauce.  Season the fried potato and onion mixture and strew over the liver.  Serve immediately.