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 until evenly coated, then spread on a baking sheet in a single layer.
04 - Bake for 25–30 minutes, turning halfway through cooking, until golden brown and crispy. For frozen fries, follow package instructions.
05 - While fries bake, cook chopped turkey bacon in a skillet over medium heat for 5–7 minutes until crisp. Transfer to paper towel-lined plate to cool, then crumble into bits.
06 - Transfer cooked fries to an oven-safe serving dish. Sprinkle cheddar and mozzarella cheese evenly over the top.
07 - Return dish to oven for 3–5 minutes until cheese is fully melted and bubbly.
08 - 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.