1. With meat mallet or dull edge of French knife, pound each cutlet to 1/8 inch thickness. Cut cutlets into pieces about 3" by 2".
2. Arrange ham on half of veal pieces, cutting ham to fit and making sure that ham pieces are slightly smaller than veal. Top with cheese, cutting the same as for ham. Sprinkle ham-and-cheese-topped veal with sage; top with remaining veal pieces. With meat mallet or dull edge of French knife, pound edges of each stack to seal in ham and cheese.
3. In pie plate, beat egg. On waxed paper,combine flour, salt, and pepper. Dip veal stacks into egg, then coat with flour mixture.
4. In 12-inch skillet over medium-high heat, heat butter or margarine and salad oil until hot. Cook veal until browned on both sides, about 3 to 4 minutes. Add water, stirring to loosen brown bits from bottom of skillet.