Drain some of the oil from the tuna, but do not let it drain completely. First puree the tuna and stock, then stir in the mayonnaise. Season to taste with salt, pepper and lemon juice. Wash parsley, shake dry and cut into fine strips.
Drain the capers.
Depending on the size, cut the slices of veal in half and arrange loosely on a large plate. Spread tuna sauce over it and season with pepper. Sprinkle with capers and parsley. Garnish with caper apples.
Cover and keep cool until serving.