Preheat oven to 425°F. Microwave potatoes on HIGH 7 minutes, turning potatoes halfway through cooking time. Cool potatoes slightly.
Cut potatoes in half lengthwise. Scoop potato into medium bowl, leaving 1/4-inch edge to form shell. Set shells aside. Add cheese, milk, butter, peppercorn medley and sea salt, if desired, to cooked potato; mash with potato masher. Fill shells evenly with potato mixture. Place on baking sheet.
Bake 20 minutes or until lightly browned. Twist additional peppercorn medley over potatoes, if desired.