Rinse sweet potato and pierce with a fork about 7 times. Cook in microwave for 7 minutes. Remove with a towel or oven mitt, slice it half and let it sit.
While the sweet potatos cook, chop your onion, tomato, cilantro, and green onion.
Drain and rinse the black beans and set aside.
Saute the chopped onion in oiled pan for about 3-5 min. Add cumin and chilli powder. When sweet potatoes are done, spoon out the inside into a large bowl. Season with salt and pepper.
Stir in the sauteed onions and rinsed black beans into the sweet potato mixture.
Heat some oil in a large skillet over medium heat.
Cover the tortillas with a paper towel and heat in the microwave for about 10 seconds. Reheat them if needed so that when you are ready to fill them they are warm and soft. This will prevent the corn tortillas from tearing when you roll them.
On a warmed tortilla, spoon about 2 tablespoons of the sweet potato mixture onto on one edge of the tortilla. If you picture 3 verticle lines separating your tortilla into 4 sections you want to add the mixture in a verticle line on the first quadrant.
Roll the tortilla starting on the side with the mixture till you have your taquito, then place it in the skillet with the seam side down to prevent it from unrolling. Continue to roll taquitos and place them close together in the skillet. Check your taquitos as they cook and turn them to another side when they begin to brown. About 5-7 min each side depending on how hot your skillet is.
Once done feel free to top them off with your chopped tomato, green onion, avocado, cilantro, jalapeño and salsa.