Heat olive oil in a large Dutch oven over medium-high heat.
Add chopped onions and minced garlic and sauté until onions are soft and translucent.
Add chicken to the pot and brown on all sides, about 5-7 minutes.
Add ground ginger, ground cumin, ground coriander, ground cinnamon, paprika, cayenne pepper (if using), salt, and black pepper to the pot and stir to combine.
Add chicken broth and diced tomatoes to the pot and stir to combine.
Add chopped carrots, chopped sweet potatoes, and green olives to the pot and stir to combine.
Bring the mixture to a boil and then reduce heat to low.
Cover the pot and simmer for 30-40 minutes, or until the chicken is cooked through and the vegetables are tender.
Garnish with chopped fresh cilantro (if using) and serve hot.