Caramelised Onion Tarte Tatin

If you’re making your own puff pastry, start by sifting the flour and salt into a mixing bowl. Roughly rub the butter into the flour, then pour in about 75ml of ice cold water, mixing with a knife until a rough dough forms. You want to see distinct flecks of butter without over-working, bring the dough together, return to the mixing bowl, cover and chill in the fridge for 20 minutes.

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Meanwhile, heat the oven to 190c. Melt 25g ofthe butter for the tart in a 20cm oven - proof pan. Scatter a generous pinch of salt and pepper over the butter, then lay the onion halves, cut side down on to the melted butter and cook for 5 minutes, until the flat onion halves are well charred and the onion centres are less rigid. Transfer the halves to a roasting tray, cut side up. Mix the oil, 1 tbsp of the vinegar and the brown sugar in a small bowl and brush over the onion halves. Cover the tray with foil and roast the onions in the oven for 35 minutes. Once cooked, leave the oven on.

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Back to the pastry, lightly flour a work surface and place the pastry in the centre. Using a rolling pin, roll the pastry out until it’s roughly 25 x 45 cm. Fold the top third down, then the bottom third up, Fold the dough envelope over from left to right, then roll out again to roughly three times the folded size. Repeat the folding and rolling, then cut into a rough 22cm round disc and transfer to the fridge to chill (save any scraps for cheese twists or little muffin-hole tarts).

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Lift the roasted onions onto a board and peel away any papery skins and discard them. Wipe out the pan if needed, then return to the hob. Sprinkle in the caster sugar and cook over a medium - low heat until the sugar is completely dissolved and a deep amber colour. Whisk in the remaining vinegar to deglaze the pan, remove from the heat and whisk the mustard and miso in until combined, Still off the heat, cut the remaining 50g of the butter for the tart into cubes and whisk into the caramel one by one until the caramel is thick and luscious. Allow to cool for 5 minutes before scattering over the thyme sprigs. Place the onion halves, cut side down into the caramel and loosely cover the onions with the prepared pastry, tucking any overhanging pastry into the sides.

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Return the pan to the oven to cook for 35 minutes until the pastry is puffed up and golden and the caramel is bubbling around the sides.

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While the tart is cooking, mix the mascarpone, cheddar, lemon zest and a generous grind of black pepper together in a bowl.

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Allow the tarte tatin to cool in the pan for 10 minutes before slicing into four to serve alongside spoonfuls of the cheddar mixture.