Trim fat from meat. Cut into 4 serving-size pieces. Place meat between 2 pieces of plastic wrap. Working from center to edges, use the flat side of a meat mallet to pound meat to 1/4-inch thickness. Remove plastic wrap.
Trim beans and cook, covered, in lightly salted boiling water for 4 minutes. Drain.
Spread each veal piece with cheese. Top with one-fourth of the beans and a slice of prosciutto (trim beans and fold prosciutto if necessary to fit). Fold in sides; roll up meat. Seal edges with wooden toothpicks or small metal skewers. Brush meat rolls with melted butter.
For a charcoal grill, arrange medium-hot coals around a drip pan. Test for medium heat above the pan. Place meat rolls on grill rack over pan. Cover; grill for 20 to 24 minutes for medium doneness (160 degrees F), turning once. (For a gas grill, preheat grill. Reduce heat to medium. Adjust for indirect cooking. Grill as above.)
Remove toothpicks or skewers from meat rolls. Place rolls on serving platter. Makes 4 servings.