Domino dauphinoise

Method

• step 1

  Heat oven to 170C/150C fan/gas 3½. Butter a medium-sized gratin dish (a round or oval one about 22cm wide is ideal) with a little of the butter. Slice the potatoes into very thin rounds – a mandolin or the sharp slicing blade of a box grater is good for this. As you slice, stack the potatoes in piles and pack them into the dish starting from the outside, building a trail around the dish and then into the middle. You want all the potatoes standing on their edges like dominoes. Slip the bay leaves between some of the slices.

• step 2

  Drizzle the cream and the rest of the butter over the potatoes, then sprinkle the thyme over the top. Season well and cook for 1 hr until the potatoes are tender and cooked through, then turn the oven up to 200C/180C fan/gas 6 for 10-15 mins to crisp up the top of the potatoes.