Scrub the potato, and prick several time with the tines of a fork. Place on a plate.
Cook on full power in the microwave for 5 minutes. Turn over, and continue to cook for 5 more minutes. When the potato is soft, remove from the microwave, and cut in half lengthwise. Season with salt and pepper, and mash up the inside a little using a fork. Top the open sides with butter and 2 tablespoons of cheese. Return to the microwave, and cook for about 1 minute to melt the cheese.
Top with remaining cheese and sour cream, and serve.