Heat olive oil in a large pot over medium heat. When oil begins to shimmer, add the diced onion. Sautee until translucent.
Add the garlic and ginger, stirring constantly for about 30 seconds.
Add turmeric, cumin, and cinnamon and stir to distribute.
Add the chickpeas, sweet potato, tomatoes, broth and coconut milk. Bring the mixture to a gentle boil and then reduce the heat to let it simmer.
When sweet potatoes are soft, add the greens.
Season stew with salt and pepper, then let the stew simmer for a few more minutes.