Cut one 12-ounce loaf country bread into 1-inch-thick slices. Grill over medium heat until marked, 2 minutes per side; cut into cubes. Cut 1 each zucchini, yellow squash and red onion into 1/2-inch-thick slices; cut 1 red bell pepper into quarters. Brush the vegetables with olive oil, season with salt and pepper and grill until tender, about 5 minutes. Chop the vegetables and toss with the bread cubes, 1 pint halved cherry tomatoes, 1/2 cup torn basil, 1/2 cup olive oil and 1/4 cup red wine vinegar. Season with salt and pepper. Top with shaved ricotta salata.