HEAT oven to 375°F. Cut potatoes in half lengthwise; scoop out centres, leaving 1/4-inch-thick shells. (Reserve centres for another use.) Cut shells crosswise in half.
PLACE shells, skin-sides down, on baking sheet; brush insides with oil. Bake 15 min. or until golden brown
MICROWAVE Cheez Whiz in microwaveable bowl on HIGH 3 min, stirring after 1-1/2 min. Pour into potato shells; top with remaining ingredients.