1 (3- to 3-1/2-pound) chicken
Coarse salt and freshly ground black pepper
2 tablespoons ground sumac-powder
5 tablespoons olive oil, divided
2 large red onions (about 1 pound), sliced thinly
2 large garlic cloves, minced
2 tablespoons chopped fresh flat-leaf parsley
3/4 pounds dense bread (such as farm bread or pane de casa), cut into 1-inch cubes
3 Kirby cucumbers, quartered lengthwise, cut into 1/4-inch slices, and tossed with a big pinch of salt
1 large ripe summer tomato, cored and cut into chunks
Juice of 1/2 lemon, or to taste
Cut the back bone out of the chicken with kitchen shears and flatten the chicken. Season it generously with salt and pepper on both sides. Make a paste with the sumac and 2 tablespoons of olive oil, and rub the paste into both sides of the chicken. Refrigerate on a plate—no need to cover—for about 8 hours. Or, if you haven’t planned ahead, just leave the seasoned chicken on the counter while you prepare the onions and bread.
Heat the oven to 375°F.
Put the onions and the remaining 3 tablespoons of olive oil in a large skillet over medium-high heat. Salt the onions and cook, stirring once in a while, until they are limp and turning gold at the edges, around 9 minutes. Add the garlic and parsley, and cook until fragrant, about 30 seconds. Scrape the onions into a large mixing bowl and add the cubed bread. Toss.
Oil a casserole dish large enough to hold the bread in a single layer (I use a 12-inch round terra-cotta dish). Scrape in the bread and onions, and spread them out. Set the chicken on top of the bread and roast for 1 hour.
Set the chicken on a cutting board and let it rest for 10 minutes.
Scrape the bread out into a big mixing bowl and let it cool for about 5 minutes. Add the cucumbers and tomato, squeeze in the lemon juice, and toss. Check for salt and pepper, and add more lemon juice if you want.
Pile the salad onto a platter. Cut the chicken into quarters and arrange it around the salad. It’s ready to serve.