Source: https://www.runningwithspoons.com/black-bean-taco-filling/
Rating: 9/10

Add the oil to a medium skillet set over medium heat. When the oil is hot, add the onion and cook until it begins to soften, ~2 minutes, stirring occasionally.
Use a potato masher or the back of a fork to mash half the beans (~1 can’s worth). Add all the beans along with the corn, spices, salt, and salsa to the skillet, mixing well to ensure that everything is evenly distributed. Cover and let cook for 5 minutes.
To serve, spoon desired amount of filling into hard or soft taco shells and top with toppings such as: cheese, pico de gallo, diced tomatoes, salsa, guacamole, avocado, shredded lettuce, cilantro, etc. Store any extra in a sealed container in the fridge for up to 5 days and reheat in the microwave before serving.