Preheat the oven to 400. Scrub the outside of the sweet potatoes and place on a baking sheet in the oven for 20-35 minutes until they are soft to the touch. Remove from the oven. Place in the fridge or outside, until cool enough to handle.
Meanwhile, drizzle half of the olive oil in the saute pan over medium heat. Add the onions and saute for about 5 minutes until just barely starting to change color. Add the carrots, a splash of water, increase the heat to just below high and saute/steam until the carrots are tender to the bite, about 5-10 more minutes. You may want to add more water as necessary, if the veggies start to stick to the pan.
Stir in the tomatoes, cumin, cocoa, coriander, and chili powder. Taste. Add more spices if desired. Allow the liquid from the tomatoes to absorb slightly for about 5 minutes. Stir in the black beans and greens. Season to taste with half of the salt and pepper.
When the sweet potatoes are cool enough to handle, gently peel away the skin. Mash in the lime zest and juice. Add salt and pepper to taste.
Once the beans & vegetables are thick, scoop it into a small baking dish (larger if you double the recipe). Dollop on the sweet potatoes until the top of the beans are covered. Drizzle on the remaining olive oil to help the top become more crispy and golden. An extra sprinkle of salt and pepper on top is also a lovely finish.
Place in the oven, increase the heat to 450 and bake until the sweet potatoes are just starting to turn golden on the edges.