PREHEAT oven to 450°F. Cut potatoes in half lengthwise; scoop out centres, leaving 1/4-inch-thick shells. Cut shells crosswise in half. Place, skin-sides down, on baking sheet; brush with butter.
BAKE 20 min. or until golden brown.
FILL shells evenly with Velveeta. Bake an additional 4 to 5 min. or until Velveeta begins to melt. Top with remaining ingredients.