Place rack in top third of oven, add sheet pan + preheat oven to 475°; peel (or don't peel!) potatoes, cut into ½-inch sticks, mix with 4 tbsp oil + salt/pep; carefully remove hot pan from oven, spread fries onto pan + bake 15 min; flip fries over, reduce heat to 425° + bake 10-15 min more until golden

Heat lightly oiled skillet over med-high; pat pork tenderloin dry + sear 2-3 min per side until warmed through; mix ¼-½ cup sauce + warm 1 min

Cut ½ of pineapple into thin slices; divide fries + pork to plates + top pork with sliced pineapple