Preheat the oven to 200°C fan. Spray a baking sheet with low-calorie cooking spray.
Rinse the potatoes in cold water and pat dry. Scatter evenly over the baking sheet and spray well with low-calorie cooking spray. Season with salt and pepper. Place in the oven and cook for around 35 minutes, shaking the tray halfway through to ensure even cooking. The fries should be golden brown and soft in the middle.
While the fries cook, spray a frying pan with low-calorie cooking spray and fry the bacon and onions until cooked through.
When the fries are cooked, top with the bacon, onions and the diced turkey. Dot over the brie pieces and add small spoonfuls of the cranberry sauce. Sprinkle over half the sage.
Return to the oven for 5-10 minutes until the turkey is piping hot and the brie is melted.
Sprinkle over the remaining sage and serve.