Bake potatoes in a 300-degree oven for around 90 minutes. When cooled, cut in half and scrape out contents, saving skins. In mixing bowl, combine the rest of your ingredients (reserving some cheese for later). Add potatoes one at a time to this mixture, mixing as you go. Put mixture back into potato skins and bake uncovered for 30-40 minutes. Remove from oven, add reserved cheese and chives as a garnish.