Step 1

If using breasts that are larger than 8 ounces and/or more than ¾ inch thick at the thicker end, halve the breasts horizontally before pounding. If the chicken sticks when flipping, gently release it from the cooking grates by sliding tongs underneath, going with the direction of the grate. Ripe, in-season tomatoes are best here but if they are unavailable, supermarket vine-ripened tomatoes will work; plum tomatoes are too dry. Look for fresh mozzarella balls labeled “ciliegine”; if they’re unavailable, cut one 8-ounce ball of fresh mozzarella into ½-inch pieces. This recipe can be halved, but we recommend grilling the full amount of chicken, which is nice to have on hand. The panzanella can be served warm or at room temperature.

Step 2

Pound chicken gently with meat pounder until ½ inch thick. Whisk water, fish sauce, honey, 1 teaspoon salt, and ⅛ teaspoon pepper together in small bowl. Transfer mixture to 1-gallon zipper-lock bag. Add chicken, press out air, seal bag, and turn bag so contents are evenly distributed. Refrigerate for 30 minutes.

Step 3

While chicken marinates, whisk olive oil, vinegar, shallot, Dijon, remaining ¼ teaspoon salt, and remaining ¼ teaspoon pepper in large bowl; set aside. (Dressing can be refrigerated for up to 3 days.)

Step 4

FOR A CHARCOAL GRILL : Open bottom vent completely. Light large chimney starter filled with charcoal briquettes (6 quarts). When top coals are partially covered with ash, pour evenly over grill. Set cooking grate in place, cover, and open lid vent completely. Heat grill until hot, about 5 minutes.

Step 5

FOR A GAS GRILL : Turn all burners to high; cover; and heat grill until hot, about 15 minutes. Leave all burners on high

Step 6

Drizzle cut sides of bread evenly with 2 tablespoons vegetable oil. Remove chicken from refrigerator and open 1 corner of bag to drain and discard excess marinade. Add remaining 1 tablespoon vegetable oil to chicken, reseal bag, and turn to evenly coat.

Step 7

Clean and oil cooking grate. Place bread, cut side down, on half of grill. Place chicken, skinned side down, on other half of grill. Cook (covered if using gas) until bread is well browned and charred at edges, 2 to 4 minutes, moving as needed to ensure even browning. Cook chicken until dark grill marks develop and breasts register 160 degrees, 3 to 5 minutes per side. Transfer bread and chicken to cutting board; let rest for at least 5 minutes.

Step 8

Cut bread and chicken into ¾-inch pieces. Rewhisk dressing to combine and add bread, chicken, tomatoes, and cucumber, tossing to evenly coat. Season with salt and pepper to taste. Transfer to serving platter and top with mozzarella and basil. Serve.