Cut the veal into thin slices and flatten with a wooden mallet. Place a slice of ham over each slice of meat with a sage leaf in the center. Roll them up and close them with a toothpick as you would a safety pin (it should not go across the involtini but make a stitch along the sides). Put the oil and butter in a saucepan. Lightly dust the involtini with flour and sauté over medium flame for 3 mins. Add wine and simmer for another 2 mins. Add salt and pepper to taste. Arrange the involtini on a serving platter. In the skillet used to cook the involtini, let the cooking juices reduce for a minute, then pour over the involtini. Serve immediately.