Tuna Panzanella Salad

Name: Tuna Panzanella Salad
Ingredients: 1 8-ounce piece rosemary focaccia (about 8 ounces); 5 tablespoons extra-virgin olive oil; 1 1/2 pounds assorted heirloom tomatoes, roughly chopped; 1 small head escarole, trimmed and chopped; 2 Persian cucumbers, quartered lengthwise and sliced 1/4 inch thick; 1 cup fresh basil, roughly chopped; 2 tablespoon capers, drained; 2 tablespoons red wine vinegar; Kosher salt and freshly ground pepper; 2 7-ounce jars oil-packed tuna (preferably Italian), drained and flaked