Heat oven to 400 degrees. Prick potatoes in 4 or 6 place. Bake potatoes 50 to 60 minutes until tender and skins are crisp. Cut potatoes crosswise into 4 thick slices. Scoop out alittle potato from the center. Season with salt and pepper. Spread each hollowed out center with a1/2 teaspoon of mustard. Cut up Brie cheese into 16 chunks and place in each center. Sprinkle with Chives. Bake in 400 degree oven for another 15 to 20 minutes until cheese melts and browned in spots.