HEAT oven to 425°F.
RINSE potatoes; drain on paper towels, then pat dry.
BRUSH 1 Tbsp. margarine onto bottom and side of 9-inch pie plate. Toss potatoes with combined remaining 2 Tbsp. margarine and 1/4 cup cheese; arrange potato slices, in several layers, on bottom and up side of pie plate. Sprinkle with remaining cheese.
BAKE 1 hour or until potatoes are tender. Loosen potatoes from side and bottom of pie plate. Invert immediately onto plate; top with chives. Cut into wedges.