Cut veal in 8 pieces; pound very thin, about 1/8-inch thick. Top each of 4 pieces with 1 ham slice and 2 cheese slices (trim cheese and ham to be slightly smaller than veal slices). Top with remaining veal slices and press edges together to seal. Dip in flour, then in a mixture of the egg and milk, and last in the bread crumbs.
Melt butter in 12-inch skillet. Add meat and cook, over medium heat, about 10 minutes or until golden brown, turning once.
Remove to warm platter. If desired, deglaze pan with some white wine and pour over meat. Garnish with water cress.