Preheat your oven to 400F, and finely dice sweet potatoes into cubes about 1cm in width all around. Spread evenly onto a baking mat or parchment paper lined tray and bake for 30-35 minutes. Cubes should be cooked, but still a little firm, as they will cook more later.
Prepare your peppers by charring them directly over your stove burner. The skin of the peppers should blacken, and after you let cool, you can peel the burnt skin off. The peppers should then be nice and tender, and you can remove seeds too.
Make your sauce by blending the onion, garlic, veggie broth, chipotle peppers, adobo sauce, freshly charred peppers, soy sauce, tomato paste, apple cider vinegar, maple syrup and spices. Blend until fairly smooth. As an optional step, you can dry toast your spices over a pan on medium heat before blending, to unlock more flavour.
In a large skillet or sauce pan, add your black beans, sweet potato, and blended sauce. Cook over medium heat, bringing the sauce to a bubble, and simmering on a low medium heat until thick. Allow the potatoes and black beans to absorb some of the sauce, and taste, adding salt and pepper as needed.
Serve with sweet potato tortillas, or tortillas of choice. Enjoy!