Preheat the oven to 375 degrees . Brush both sides of each bread slice with olive oil, place on a baking sheet and bake for 10 minutes. Rub the garlic halves on each toast.
In a large salad bowl, add the chopped garlic; whisk in the yogurt, lemon juice and 2 tablespoons olive oil. Toss with the lettuce, tomatoes, onion and capers. Season with pepper. Divide the salad among 6 plates and top each with 2 toasts.