Place chicken between 2 sheets of heavy-duty plastic wrap, and flatten to 1/4-inch thickness using a meat mallet or rolling pin.
Stir together garlic and next 4 ingredients. Rub mixture on chicken. Place in a shallow dish or heavy-duty plastic bag; cover or seal, and chill 3 hours.
Place chicken on a rack coated with cooking spray in a broiler pan.
Broil 5 1/2 inches from heat (with electric oven door partially open) 5 minutes on each side or until done. Place lettuce leaves on half of bread slices; top with chicken. Spoon 1/4 cup Fresh Salsa over each chicken breast; top with remaining bread slices.