In a large Ziploc bag, combine lemon juice, oil, garlic, salt, cumin, black pepper, paprika, turmeric, red pepper flakes, and cinnamon. Close the bag and shake to mix well.
Add chicken. Close the bag and toss in the bag to ensure it is well coated with the marinade. Lay flat in the refrigerator and marinate for at least 1 hour (longer is better).
Preheat oven to 425 degrees.
Remove the chicken from the refrigerator and add the sliced onion to the bag. Toss well to coat the onion.
Spray a 9 x 13 baking dish with non-stick spray. Pour the chicken, onion, and marinade into the baking dish.
