Heat the coconut oil in a large, heavy soup pot over medium heat. Add the onions and lower heat until they are sizzling kind of quietly. Once the onions are a bit soft and translucent, add the cinnamon, cumin, coriander and chili flakes. Slowly sauté and stir this mix until the onions are really, really soft, about 6-7 minutes. Add the garlic and sauté until fragrant, about 1 minute.
Add the chopped dates, carrots and sweet potatoes. Season with salt and pepper. Stir to coat the vegetables in the spices and oil. Add the tomatoes and stir. Add the vegetable stock. Bring the soup to a boil and simmer until the sweet potatoes are just tender, about 10-12 minutes.
Add the chopped yellow peppers and chickpeas and stir the soup. Season the whole thing again with salt and pepper. Simmer until the yellow peppers are tender and the sweet potatoes are quite soft, about 5 minutes.
Add the greens to the pot (and more stock if necessary) and cook for 1 minute, or until just-wilted. Check the soup for seasoning and serve it hot with cooked grains, drizzles of olive oil, lemon zest and chopped herbs.