Simmer veal lungs, heart and tongue in vinegar water with bay leaves over low heat. Leave to cool for one night and cut into tender strips a day later.
Roasting: Stir butter and flour in hot saucepan until brown, add stock and water. Add the chopped onions, cucumbers, capers and simmer for 1/2 hour over medium heat. Press the sauce through a sieve. Add the chopped veal lung, heart and tongue to the sauce form. Season to taste with salt and freshly ground pepper. Serve with baked bread dumplings garnished with parsley.