Preheat the oven to 400°F (200°C).
Wash and dry the russet potatoes.
Pierce the potatoes with a fork several times.
Rub the potatoes with olive oil and season with salt.
Place the potatoes directly on the oven rack and bake for 45-60 minutes.
While the potatoes are baking, cook the ground meat in a skillet over medium heat until browned.
Add the taco seasoning, black beans, and corn to the skillet; stir well.
Cook for an additional 5-7 minutes, stirring occasionally.
Remove the potatoes from the oven and let them cool slightly before slicing them open.
Spoon the meat mixture into the potatoes and top with cheddar cheese.
Return the potatoes to the oven and bake for an additional 10 minutes until the cheese is melted.
Serve topped with sour cream and cilantro.