01 - Preheat oven to 425°F.
02 - If using fresh potatoes, soak cut fries in cold water for 30 minutes, then drain and pat dry thoroughly.
03 - Toss fries with vegetable oil and spread on a baking sheet in a single layer. Bake for 25-30 minutes, turning halfway through, until golden and crispy. If using frozen fries, follow package baking instructions.
04 - While fries bake, cook chopped turkey bacon in a skillet over medium heat for 5-7 minutes until crisp. Transfer to a paper towel-lined plate to cool, then crumble into bits.
05 - Transfer cooked fries to an oven-safe serving dish. Sprinkle evenly with shredded cheddar and mozzarella cheese.
06 - Return fries to the oven for 3-5 minutes until cheese is fully melted and bubbly.
07 - Remove from oven, top generously with turkey bacon bits, and sprinkle with chives or green onions if using. Serve immediately with sour cream on the side if desired.