Spiedini are any mix of ingredients cooked on a skewer.
Mix together white wine, lemon juice, 1/2 cup oil, a few sprigs of chopped rosemary, and salt and pepper to taste. Add shrimp; marinate for 1 hour.
Heat a grill to medium hot and place grid 4 inches above coals. Remove shrimp from marinade and wrap a third of a piece of prosciutto around middle of each shrimp. Place shrimp on skewers, alternating with bread cubes, tucking a small sprig of rosemary between shrimp and bread. Set aside until ready to grill.
Brush with oil and grill for 2 to 3 minutes on each side.