Mix the sumac and 2 tbs olive oil in a small bowl. Rub the mixture over the chicken and place the chicken on a platter in a single layer. Sprinkle with the salt and pepper. Refrigerate 8 hours or overnight.

Heat a large skillet over medium heat. Add 3 tbs of the olive oil and saute the onion until it is tender but not browned.

Add the garlic and parsley and cook for about 30 seconds or until the garlic is fragrant.

Place the bread cubes in a large bowl. Add the sauteed onion, parsley and garlic; toss to coat.

Preheat oven to 375 degrees F. Coat a large baking dish (13 x 9) with the remaining 1 tbs olive oil.

Place the bread mixture in the pan so the bread is a single layer.

Place chicken on top and bake for 60 minutes, or juices run clear.

Remove chicken to a platter and keep warm.

Place the bread in a bowl and add the cucumber, tomato and the lemon juice; toss to combine. Add additional salt and pepper to taste. More lemon juice may be added if you desire a tarter salad.