In a small saucepan cook garlic in oil over moderately low heat, stirring, until softened and cool. In a small food processor or blender puree tomatoes, basil, oil, pine nuts, and parmesan until pesto is smooth. In a bowl toss steak with half of pesto and spread remaining pesto on bread, top with some lettuce leaves. Divide steak among 4 bread slices and top with remaining 4 slices.
Recipe courtesy of Gourmet Magazine