Tips: If you have one, use a mandolin or food processor fitted with a slicing blade to slice the potatoes and parsnips thinly and evenly. At the end of the cooking time, to test if the vegetables are tender, insert a sharp knife through the middle of the potatoes and parsnips. The knife should slide in easily, and the vegetables should feel soft. If not, give them a few more minutes. You can use orange-fleshed sweet potatoes in place of some or all of the ordinary potatoes for a delicious and sustaining alternative. Other root vegetables such as Jerusalem artichokes, carrots, swede (rutabaga) or turnips would also work well in combination with the potato.

1. Peel the potatoes and parsnips and cut them into thin slices using a sharp knife. Place them in a steamer and cook for 5 minutes. Leave to cool slightly.
   
   
2. Meanwhile, pour the cream and milk into a heavy pan, add the crushed garlic and bring to the boil over a medium heat.
   
   
3. Remove the pan from the heat and leave to stand at room temperature for about 10 minutes to allow the flavour of the garlic to infuse into the cream and milk mixture.
   
   
4. Lightly grease a 10in long, shallow rectangular earthenware baking dish with butter or oil. Preheat the oven to 350`F.
   
   
5. Arrange the thinly sliced potatoes and parsnips in layers in the greased earthenware dish, sprinkling each layer of vegetables with a little freshly grated nutmeg, a little salt and plenty of ground black pepper.
   
   
6. Pour the cream and milk mixture into the dish and then press the sliced potatoes and parsnips down into the liquid. The liquid should come to just underneath the top layer of vegetables.
   
   
7. Cover the dish with a piece of lightly buttered foil or baking parchment and bake for 45 minutes.
   
   
8. Remove the dish from the oven and remove the foil or paper from the dish. Sprinkle the grated Cheddar cheese over the vegetables in an even layer.
   
   
9. Return the dish to the oven and bake uncovered for a further 20-30 minutes, or until the potatoes and parsnips are tender and the topping is golden brown.