Pear & Potato Tart with Montagnolo Affine

You will need a 23cm tart tin. First, make the walnut pastry. Put the flour, butter and salt into the bowl of a food processor and pulse until the mixture resembles breadcrumbs (avoid over-mixing if possible). Slowly pour the cold water in through the top of the processor a little at a time, until the mixture comes together in a soft but not sticky dough. Put the walnut pieces in with the pastry dough and pulse them briefly to combine, then dust your work surface lightly with flour and tip the pastry out on to it. Roll the pastry out thinly enough to line your tin, then lift it carefully into the tin and put it in the fridge to chill for at least 15 minutes before using.

While the pastry chills, you can get on with the filling. Place a large pan of cold water over a high heat and bring up to the boil, then add the diced potatoes. Simmer until just tender (5-8 minutes) then drain the potatoes thoroughly and put them back in the hot, dry pan to steam dry for a little longer. Pre-heat the oven to 200°C (Gas Mark 6).

In a large frying pan, melt half of the butter with a good splash of olive oil over a low-medium heat, then add the onions and fry gently until really soft – about 10 minutes. Turn up the heat to caramelise the onions, letting them colour just a little, then use a fish slice or slotted spoon to lift them out of the pan and on to a plate to cool. Put the pan back on a medium-high heat and add the pears, together with the remaining butter. Fry them for 3-4 minutes, turning regularly, until they are lightly coloured, then lift them out on to the plate to cool with the onions.

When the pastry case has had its chilling time in the fridge, and the oven has come up to temperature, take the flan tin out of the fridge and put a layer of foil over the pastry. Put baking beans on top of the foil to weigh it down (if you don’t have these, you can use some dried beans or lentils, even rice – just be sure to keep them well within the foil) and put the tin into the hot oven to cook for 15 minutes, until the pastry is set and very slightly golden in colour. Take the tin out of the oven, remove the foil and beans, then put it back in to bake for another 10 minutes, or until it is properly golden and cooked through. Turn down the oven to 180°C (Gas Mark 4).

Take the cooked pastry case and scatter in the cooled pear and onion, together with the cooked potatoes, the walnuts and about three-quarters of the cheese. Whisk together the cream, milk, egg and thyme leaves in a large mixing bowl or jug, then season with salt and pepper (remembering that blue cheese is quite salty) and pour into the pastry case to cover the cheese and pear mixture. Dot with the remaining cheese and decorate the top with the reserved sprigs of thyme, then bake for about 30 minutes, or until the tart is lightly set with just a faint ‘wobble’. Serve warm, or leave to rest and serve at room temperature.