Chicken Kebabs

" Ingredients:
2 pounds skinless, boneless chicken breasts, trimmed of any fat and cut into cubes
1/2 cup extra-virgin olive oil
3 tablespoons fresh lemon juice
1 small onion, grated
1/2 teaspoon ground cinnamon
1/2 teaspoon ground cardamom
1 teaspoon dried or fresh thyme leaves
Salt and freshly ground black pepper
1 teaspoon ground cumin
1 teaspoon Baharat - Arabian Style
1/2 teaspoon Spanish Paprika
10 (10-inch) wooden or metal skewers

Preparation:
Marinate the chicken cubes in a glass or ceramic bowl or pan with the olive oil, lemon juice, onion, cinnamon, cardamom, thyme, salt, pepper, cumin (if using), Baharat, and paprika for 6 hours, covered, in the refrigerator, turning the cubes occasionally.
Preheat a gas grill for 15 minutes on high or prepare a hot charcoal fire. Skewer the chicken cubes so they touch each other but do not press against each other. If possible, use a skewer rack so the chicken grills without touching the grilling grate. Grill until golden brown, 20 to 30 minutes, turning frequently. Serve hot."