For the Wiener Schnitzel, pound the veal escalopes thin (preferably between plastic wrap) to a thickness of about 6 mm.
Salt the schnitzel evenly on both sides.
In a plate, beat the eggs with a fork and stir in the milk. Dredge the cutlets in flour on both sides, pass through the eggs and then coat in breadcrumbs.
Heat plenty of clarified butter (about 3 cm high) in a large frying pan. Place the Wiener Schnitzels in the hot fat and brown, swirling the pan repeatedly (this way the Schnitzels are constantly surrounded by hot fat). Turn and bake until done in 3-5 minutes.
Lift out the Wiener Schnitzels and drain on paper towels.
For the dressing, mix the white wine vinegar with tarragon mustard, salt, pepper and a pinch of sugar. Pour in sunflower oil and stir to make a creamy marinade. Marinate the chopped lettuce with the dressing.
Arrange the Wiener Schnitzel on warmed plates, garnish with lemon wedges if desired and serve with the marinated salad.