Heat gas or charcoal grill. In large bowl, mix cucumber, bell peppers, onion, olives, basil and dressing. Set aside.
Rub both sides of each slice of bread with cut side of garlic clove; brush both sides of each with oil. Discard garlic.
Place bread slices on grill over medium heat. Cook 4 to 6 minutes, turning once, until golden brown. Remove bread from grill. Cut into 1/2-inch cubes.
Add greens, spinach and toasted bread cubes to salad mixture; toss to combine. Sprinkle with cheese.