Wash potatoes; bake at 400° for 1 hour or until done. Let cool to touch. Cut a 1-inch lengthwise strip from top of each potato; carefully scoop out pulp, leaving shells intact. Mash pulp in a large bowl. Add cheese and next 7 ingredients; stir well.
Spoon potato mixture evenly into shells. Bake, uncovered, at 375° for 20 minutes or until thoroughly heated. Sprinkle evenly with 2 tablespoons chives.