Crisp potato cake

• medium-sized roasting potato↗1.3kg kg

  such as King Edwards or Maris Pipers

• butter↗3 tbsp tbsp

  melted

• thyme↗1 tbsp tbsp

  leaves and 1 thyme sprig

• nutmeg
• olive oil↗2 tbsp tbsp
• sea salt↗

  to serve

Step-by-step instructions

1. 1

   Heat the oven to 220 °C (fan 200 °C, gas mark 7). Peel the potatoes and place them in a pan of cold, salted water. Bring to the boil, simmer for 3 minutes and drain. When cool enough to handle, slice a few potatoes very neatly. Coat the bottom of a round, oven‑proof, non‑stick pan with melted butter, then place a sprig of thyme in the centre. Lay a slice of potato in the centre, then arrange the remaining slices over the base of the pan, overlapping them in concentric circles. Slice the rest of the potatoes and put them in a bowl; add the remaining butter, a pinch of nutmeg, the thyme leaves and season with salt and pepper. Toss everything together, then tip the seasoned potatoes over the arranged slices and press down gently to flatten. The potato cake can be prepared up to a day ahead and kept covered in the fridge.

2. 2

   Place the cake in the oven on the lower rack beneath the beef. Every now and then, remove it, press it down with a fish slice and drizzle a little olive oil over the surface. Bake for 1 hour to 1 hour 15 minutes, until the sides are brown and crispy. Carefully invert the cake onto a serving dish or board, scatter with sea salt and serve cut into wedges.