Preheat the oven to 425 degrees.
Cut the sweet potatoes in half and place them on a baking sheet. Cook them in the heated oven for 45-50 minutes (If you are short on time, see my directions for microwaving the sweet potatoes in the paragraphs above).
While the sweet potatoes are baking, cook the diced onion in a large frying pan with 1 tbsp of olive oil. Cook the onion for 5-7 minutes, until it is translucent.
If you are using frozen corn, warm it in the microwave or on the stove. If you are using fresh corn, boil it in water then cut it off the ear.
When the sweet potatoes are finished cooking, scoop most of the sweet potato out of each half, leaving a bit of the potato and the skin. Put the scooped out potato into a large bowl.
In the same large bowl with the sweet potato, add the cooked corn, cooked onion, black beans, cheddar cheese, lime juice, cilantro, cumin, and garlic salt. Mix until everything is well combined.
Put the filling back into the sweet potato skins and top with a little more cheddar cheese.
Turn the oven onto broil (at 450 degrees) and put the sweet potatoes in for 5 minutes to let the cheese melt.
Remove from the oven and let cool for a few minutes before eating.
Top with sour cream and enjoy!
