In a saucepan, combine milk, cream, garlic, nutmeg (or cinnamon), and thyme. Heat gently until almost boiling.
Peel and thinly slice the potatoes. Add them to the hot cream mixture and simmer for 6–7 minutes, stirring occasionally.
Preheat oven to 200°C (390°F). Grease a baking dish with butter.
Layer the potatoes in the dish, seasoning with salt and pepper and sprinkling cheese between layers. Finish with a generous layer of cheese on top.
Bake for 20–25 minutes until the top is golden and bubbling.
