For the Grilled Chicken: Combine chicken, lemon juice, and garlic in a bowl and marinate for 30
minutes at room temperature, or cover and refrigerate as long as overnight.
Heat an oiled grill or grill pan to medium-high. Drain any excess liquid from chicken and
discard garlic. Season chicken with salt and pepper.
Grill chicken until cooked through and lightly charred, 6 to 7 minutes per side.
Cut chicken into 1-inch-thick slices. Keep warm.
Prepare the salad: Heat oven to 350ºF. Toss bread cubes with 2 tablespoons oil and spread in a single layer on a large baking sheet (use two sheets if necessary).
Bake, tossing halfway through, until golden and crispy, about 15 minutes.
Meanwhile, whisk together vinegar, lemon juice, anchovies, garlic, and remaining 2 tablespoons
oil. Stir in olives and capers. Season with pepper.
Combine toasted bread, tomatoes, cucumbers, arugula, basil, and onion in a large serving bowl. Toss with dressing and season with salt and pepper.
Sprinkle with ricotta salata and top with sliced chicken.