1.2kg (2 1/2lb) Maris Piper or King Edward potatoes, finely sliced with a mandolin
1 celeriac, finely sliced with a mandolin
100g (3 1/2oz) Gruy?re, grated
Instructions
Preheat the oven to gas 4, 180°C, fan 160°C. Put the cream and milk in a large pan and bring to a gentle simmer. Add the crushed garlic and continue cooking for 3 minutes.
Add the potatoes to the cream mixture and simmer for 4-5 minutes, until just cooked. Remove with a slotted spoon and set aside (you may need to do this in batches). Repeat with the celeriac, simmering for 2-3 minutes until just cooked. Remove the cream mixture from the heat and set aside until needed.
Rub a large baking dish with the remaining garlic; discard. Layer up the potatoes and celeriac in the dish, adding a little of the cream mixture and some seasoning every 2-3 layer. Scatter over the cheese and bake for 30 minutes, or until the top is golden and crisp. Serve with slow-roast sirloin of beef and chargrilled broccoli.