Preparation

1. Preheat the oven to 375.
2. Cut the potatoes into slices about 1/8" think.
3. Cut the leeks in half lengthwise, then into very thin slices.
4. Butter a shallow, round 10" baking dish.
5. Arrange a layer of potato slices in the pan in overlapping circles.
6. Brush with about one fourth of the melted butter.
7. Top with about half of the leeks and half of the thyme.
8. Season with salt and pepper.
9. Repeat with another layer of potatoes and the remaining leeks and thyme.
10. Top with a final layer of the best looking potato slices.
11. Brush the top layer with about one fourth of the melted butter and lightly sprinkle the cinnamon on the top.
12. Cover the pan with aluminium foil.
13. Place a heavy skillet or baking dish on top to press the potatoes into a compact mass.
14. Bake for 30 minutes.
15. Remove the skillet and foil and baste the top layer with the remaining butter.
16. Continue baking for about 30 minutes, until the potatoes are very soft and the top and bottom layers have started to caramelize.
17. If the potatoes begin to char, cover the top with foil.
18. Cool for 15 minutes before serving Serves 4 to 6.