Wash the schnitzel and dab dry. Cover each half of the schnitzel with a slice of cheese and 1/2 slice of ham. Fold the schnitzel together and fix with wooden skewers. Mix flour with salt and pepper.
Whisk egg and milk. Turn the schnitzel in flour, then in the egg and finally in breadcrumbs. Fry in hot fat at medium heat for 8-10 minutes on each side. Serve with tomato, chives and lettuce if desired.