How to Make It
Preheat grill to high. Brush cut sides of baguette with 1 Tbsp. olive oil and sprinkle with salt. Grill bread, cut sides down, until lightly charred, about 1 minute. Let cool and cut into 1-inch pieces.
Brush chicken all over with 1 Tbsp. olive oil and sprinkle with salt. Grill, turning once, until cooked through, 6 to 10 minutes. Let cool slightly.
Combine tomatoes, cucumber, olives and bread in a large bowl. Whisk together remaining 6 Tbsp. oil, lemon juice, yogurt and garlic in a small bowl. Season with salt and pepper. Toss dressing and basil with bread mixture to coat. Divide among 4 dinner plates.
Thinly slice chicken and place on top of salad. Serve immediately.