You’ll Need:1 1/2 pounds flank steak 1/2 cup balsamic vinegar 1 (10 ounce) bag spinach, stems removed, leaves sliced into strips Salt and ground black pepper 4 tablespoons Filippo Berio Extra Virgin Olive Oil 1 1/2 ounces Parmesan cheese Crusty Italian BreadDirections : Place the steak and vinegar in a