Serves eight

Ingredients

For the pastry:300g plain flour1/2 teaspoon fine salt190g unsalted butter, chopped35g parmesan4 tbsp iced water

For the filling350g smoked streaky bacon1 tbsp olive oilSalt & pepper1kg leeks – 550-600g – cut 1.5cm30g butter250g Westcombe Cheddar10g weight picked thyme leaves320g double cream220g full fat milk6 eggs beatenSalt & pepper

Method

First make the pastry. Cut the cold butter until small pieces. Place flour in the robot coup with the salt and turn on for a couple of seconds to combine and sift the flour. Add the chopped butter and pulse for around 30 seconds until fine breadcrumbs. Add the cold water through the funnel again using pulse button for around 10-20 seconds. The mixture will still be crumbly but tip out into very large bowl and bring together working fast and not overhandling the pastry. Add a tiny bit more water (1 tsp at a time), cutting through with a knife, if required.

When the pastry has come together roll out using well-floured rolling pin and work surface and use to line the tin. Chill the pastry in the tin for at least 45 mins in fridge.

Meanwhile make the filling. Remove the skin and the seeds from the squash and cut into 1.5cm pieces. Toss with the olive oil, salt and pepper and roast at 200’c for around 30 mins. It should be soft but not really coloured. Set aside. Trim the leeks, cut lengthways, rinse and slice into 1.5cm slices. Cook gently with the butter and 1⁄4 tsp salt in a heavy based pan for around 10 mins until soft, stirring occasionally. They shouldn’t go very brown. Grate the cheese and pick the thyme leaves.

Before baking the pastry prick the base with a fork and line the tin with parchment and baking beans. Bake for 22 mins at 170’c then remove parchment and baking beans and back for a further 8-10 mins or until light golden brown.

Beat the egg white lightly with a fork and brush all over the surface of the tart case. Return to the oven for 1-2 mins to set.

Beat together the eggs, milk and cream until combined. Season to taste (around 3⁄4 tsp salt, 1⁄4 tsp freshly ground pepper.)

Put nearly one half of the cheese in the base of the tart tin then scatter over the almost half of the leeks, the thyme and the cooked squash. Layer again, reserving a little of all of the ingredients for the top. Carefully pour over the cream – egg – milk mixture and scatter the top with cheese, leeks squash, thyme – these should all be visible above the cream mixture – this will make it look nice.

Return to the oven for 45mins at 170’c. Check if it is set, if not cover (if necessary) and bake for a further 10-15 mins. Leave to cool for at least 30mins before cutting.