Method:
Preheat oven to 400°F. Prick potato all over with a fork and arrange on a baking sheet. Bake until just tender, about 1 hour; set aside until cool enough to handle. Meanwhile, preheat broiler.
Cut open potato and scoop about 1/2 cup of the cooked flesh into a medium bowl. Add sour cream, beans, salt and cumin and mash with a fork to combine. Use bean mixture to refill potato, then top with cheese and return to baking sheet or place in a small baking dish. Broil until cheese is melted and golden brown, about 2 minutes. Top with salsa and green onions and serve.