Preheat oven to 375°.
Pierce potatoes with a fork, and bake at 375° for 1 hour or until tender. Cool potatoes slightly.
Combine sour cream and cheese in a small bowl; partially mash with a fork.
Heat a small nonstick skillet over medium heat. Add diced pancetta; cook 2 minutes. Add garlic; cook 1 minute.
Split the potatoes lengthwise, cutting to, but not through, other side. Spoon 2 tablespoons cheese mixture into each potato. Top each serving with 4 teaspoons pancetta mixture and 1 1/2 teaspoons chives.