Heat oven to 425 F. Scrub and pat dry the potatoes. Rub with olive oil and sprinkle generously with salt. Bake about an hour. Remove and let them cool enough to handle.
Meanwhile, heat some oil in a skillet over medium heat. Cook onions until soft and translucent. Add red pepper and go until soft. Add corn and black beans until they look warmed through. Add the seasonings until combined, then remove pan from heat.
When potatoes are just cool enough to handle, slice them in half and scoop out the ‘innards’, leaving a ¼” rim and drop in a bowl. Line up the ‘shells’ on a sheet pan.
Mash the potato ‘innards’ with the sour cream until smooth. Stir in half of the cheese. Incorporate the vegetables from the skillet. Smash filling into potato shells, top with the rest of the cheese, and return to the oven for about 10 minutes, or until the cheese has melted to your liking.
Serve with more Sour Cream, some chopped Cilantro, even some chopped avocado or scallions.