With a fork, pierce sweet potatoes 4-5 times. Microwave until the center is tender, about 5-10 minutes. If you prefer oven baked, place in a oven-safe dish and bake at 425° F until the center is tender, about 1 hour.
In a microwaveable bowl, combine beans, tomatoes, and next 5 ingredients. Microwave for about 2 to 3 minutes, or until heated through.
Wait until potatoes are cool enough to hold, then cut each lengthwise and open, pressing a well into the center, and add the bean mixture into the well. Add a spoonful of sour cream and chopped cilantro on the tops of each potato.