GET AHEAD
Prepare to the end of step 5; cool, cover and chill. Bake for an extra 10 mins from chilled.
Put the whole, unpeeled potatoes in a saucepan, cover with cold water and bring to the boil. Cook until a skewer inserted in the centre of each just goes through – 20-25 minutes. Drain and leave to cool.
Meanwhile put the butter, shallots and garlic into a shallow pan and cook over a low heat until soft and lightly coloured, about 10 minutes.
Once the potatoes are cool enough to touch, peel off the papery skins by scraping them with a knife, and slice into 5mm-thick rings. Preheat the oven to 180°C, fan 160°C, gas 4.
Arrange half the potato slices in a buttered, shallow 1.5-litre ovenproof dish (we used a 20cm square dish). Scatter the ham hock evenly over the potatoes, then layer up the remaining slices.
Beat the cream and milk together adding the mustard, half the thyme and a good amount of black pepper and sea salt. Pour this over the potatoes; press them down gently. Scatter the soft shallots and the rest of the thyme over the surface.
Crumple a big piece of baking paper; put on the surface of the potatoes. Cook in the oven for 40 minutes. Remove the baking paper; cook for a further 20 minutes until bubbling and golden. Remove from the oven; sit for 10 minutes before serving.
ADVERTISEMENT