Place a saucepot over medium-high heat and add the coconut oil. Add the sweet potatoes with a pinch of salt and cook until they begin to brown and soften, about 3 minutes. Reduce the heat to medium-low and then add the onions, poblano, garlic, coriander, chili flakes and ginger. Cook until the onions soften and the mixture is very fragrant, 3 to 5 minutes. Stir in the vegetable stock, coconut milk and chickpeas and bring to a simmer. Cook, stirring occasionally, until the sweet potatoes are completely tender and the liquid has reduced slightly and has thickened, about 15 minutes. Stir in the cilantro and serve with a squeeze of lime on top.