Preheat oven to 220°C/200°C fan forced.
Place potatoes in a large saucepan and cover with cold water. Bring to the boil over high heat. Reduce the heat to medium-high and boil gently for 10 minutes or until just tender. Drain.
Transfer potatoes to a large baking tray. Press each potato gently with the bottom of a glass or potato masher to squash. Spray liberally with extra virgin olive oil spray and season. Sprinkle with thyme. Roast for 30 minutes or until crisp and golden. Serve.