Preheat over to 400 degrees F. Lightly spray a baking rack with olive oil spray and place over a large baking sheet, leaving space between the baking rack and the baking sheet so fat can drain off.
In a large bowl, stir together the turkey, broth, bread crumbs, 1/4 cup onion, celery, parsley, cinnamon, allspice, turmeric, and pepper until just mixed. Shape into 16 balls and place on rack.
Bake for 12-15 minutes or until light golden, turning meatballs halfway through cooking time, to brown all sides. Remove from oven and place meatballs on a large plate lined in paper towels.
Spray a large non-stick skillet with olive oil spray. Heat pan over medium- high heat. Cook sliced onion and garlic for 3-4 minutes until soft.
Stir in remaining ingredients increase heat to medium-high and bring to a boil. Gently add the meatballs, spooning sauce over the meatballs. Reduce heat and simmer, covered, for 10-12 minutes or until meatballs are cooked through, turning meatballs halfway through cooking and spooning sauce over meatballs after turning.
Remove from heat and serve over couscous or brown rice.