Caesar Salad Beef Burger on Garlic Crostini

Combine ground beef, minced garlic, salt and pepper in large bowl, mixing lightly but thoroughly. Lightly shape into four 1/2-inch thick patties. Grill over medium heat coals or medium heat gas grill setting until internal temperature reaches 160°F (70°C), 8 to 10 minutes, turning once halfway through grilling time. Season with additional salt and pepper, if desired. Meanwhile, brush both sides of bread slices lightly with olive oil. Place bread around outer edge of grid. Grill until lightly toasted, turning once. Remove bread from grid; rub both sides of each slice with garlic quarter. To assemble place one lettuce leaf on each of four slices of bread; top each with burger. Sprinkle evenly with cheese and top with remaining slices.