Preheat a large skillet over medium heat.
Add a couple of Tablespoons of olive oil to the pan.
Add the diced sweet potatoes, and sauté them until they are soft almost all the way through. If you have particularly stubborn sweet potatoes, you can very carefully add a few Tablespoons of water to the pan and quickly cover the skillet with a lid. Steam them for a few minutes until soft. I recommend adding the water with the pan off the heat.
After the sweet potatoes are soft, add the onions and peppers. Sauté until the onions are translucent, about 10 minutes.
Add the corn, sauté for 2-3 minutes.
Add the drained can of black beans. Stir to combine the filling.
Add the lime juice. Scrape up any yummy brown bits that are stuck to the pan. The lime juice will loosen them from the pan.
Add the cumin and coriander. Stir.
Add salt to taste. Add it gradually, tasting often, until you are happy with the salt level.
Serve with tortillas, shredded cheese, sour cream, salsa, and any other taco fixings you'd like.
