Preheat oven to 350 and lightly oil a 9×13 or 10×15 baking dish. Spread a thin layer of enchilada sauce over the bottom of the pan. You may need the larger size (or two smaller) depending on the size of your enchillitos.
Cook sweet potato in boiling water until soft.
Meanwhile, saute onion in large skilled until soft, adding small amounts of water to unstick. When soft, add garlic and cumin, chili powder, cocoa powder and cook one minute.
Add beans, green chiles, corn, sweet potato, and Soyrizo if using. Combine and cook on medium-low until warmed through. Coarsely mash with potato masher. Add salt and pepper to taste.
Divide bean mixture, scoop into the center of each tortilla and roll up. Place in prepared pan. Pour enchilada sauce over the top and sprinkle with cheese, if using. Bake uncovered for 30 minutes.