Best of the best gratin dauphinois

Method

1. Add the milk, cream, thyme, bay, rosemary, peppercorns, garlic and salt to a saucepan. Put over a low-medium heat and cook, stirring occasionally, for 5 minutes, or until the pan is just beginning to simmer. Remove from the heat, grate in a little nutmeg, then cover and set aside to infuse for 20 minutes. Meanwhile, heat the oven to 160°C fan/gas 4.
2. Grease a baking dish with butter and strain the warm cream mixture through a fine sieve into a large mixing bowl, discarding the solids. (If you’ve infused the cream ahead of time in the fridge, gently warm it through before using). Peel the potatoes, then use a mandoline to finely slice them lengthways directly into the warm cream mixture. When all the potatoes are sliced, use your hands to separate the slices in the cream mixture so they’re all coated in the liquid.
3. Begin layering up the dauphinoise in the baking dish, trying to keep all the slices flat and even, and packing them down tightly. Once they’re all in, pour over enough of the cream mixture left in the bowl to just cover (a few slices of potato poking out of the top are fine). The size and shape of your baking dish will dictate how much cream mixture you will need, but any leftover can be saved in the fridge for a few days and used to cook other dishes (it’s great with pork, chicken or pasta).
4. Bake the dauphinoise in the oven uncovered for 1 hour 30 minutes, or until a knife will cut through it with only a little resistance. The top should be a dark golden brown but don’t let it blacken.
5. Remove it from the oven, cover with a sheet of baking paper, then put the second baking dish on top. Fill with heavy weights such as tins and leave to press while it rests for 10-15 minutes. To serve, uncover the dauphinoise and slice into rectangles.