1.Preheat oven to hot, 200°C (180°C fan-forced). Lightly grease a shallow 6-cup ovenproof dish.
2.Heat a large saucepan on high. Spray with oil. Cook bacon 3-4 minutes, until golden. Drain on paper towel.
3.Slice potatoes thinly using a mandolin or v-slicer. Layer 1/3 potato slices in dish. Sprinkle with 1/3 bacon and 1/3 cheese. Repeat with remaining potato, bacon and cheese.
4.Add soup, cream and thyme to same saucepan. Season. Heat, stirring, until almost boiling. Pour hot soup mixture over potatoes, shaking dish to allow mixture to run through.
5.Bake, covered, 40 minutes. Uncover, bake a further 25-30 minutes, until top is golden. Set aside 10 minutes. Serve sprinkled with extra thyme.