Ingredients

• 250g/9oz plain flour
• plus extra for dusting
• 65g/2â…“oz icing sugar
• ½ tsp salt
• 3 tsp ground ginger
• ½ tsp ground cinnamon
• 125g/4½oz butter
• chilled and cubed
• 2 large free-range egg yolks
• 1 small free-range egg
• beaten
• 2 pink grapefruit
• juice and zest only
• 3 white grapefruit
• juice and zest
• 1 red grapefruit
• juice and zest
• 70g/2½oz fresh root ginger
• peeled and sliced
• 5 large free-range egg yolks
• 3 large free-range eggs
• 60g/2¼oz caster sugar
• 2 tbsp cornflour
• pinch salt
• 70g/2½oz unsalted butter
• cubed
• 300g/10½oz caster sugar
• 2 tsp lemon juice
• 140g/5oz egg whites
• at room temperature

Directions

• For the pastry
• sift the flour
• sugar
• salt
• ginger and cinnamon into a large bowl. Add the butter and
• working quickly
• rub the mixture together between your thumb and forefinger until the mixture resembles coarse breadcrumbs.
• Add the yolks and 3 tablespoons water. Using your hands
• mix to form a dough.
• Turn onto a very lightly floured work surface. Gently and quickly knead the dough until it becomes smooth. Flatten the dough into a disc and wrap in cling film. Refrigerate for 30 minutes or freeze for 10 minutes.
• Once the pastry has chilled
• roll it out thinly on a lightly floured surface. Lift the dough into the tart tin and press into the edges. Leave any excess overhanging the sides of the tart tin. Prick the base with a fork and line with baking paper. Fill with baking beans or uncooked rice and chill again for 10 minutes.
• Preheat the oven to 180C/170C Fan/Gas 4.
• For the filling
• add the juice and zest of the grapefruits to a large saucepan. Add the ginger and bring to the boil. Simmer for 10 minutes
• then strain to remove the ginger and set the juice aside to cool.
• In a separate heatproof bowl
• add the yolks
• eggs
• sugar
• cornflour and salt. Whisk to combine then set the bowl over a pan of gently simmering water (do not allow the water to touch the bowl). Pour in the grapefruit juice and whisk the mixture for about 15 minutes
• or until it starts to thicken. Add the butter piece by piece
• whisking all the time for about 15 minutes
• or until the mixture is very thick. (If the mixture is taking too long to thicken
• transfer the mixture to a pan and heat gently until thick.) Place some cling film on the surface of the curd to prevent a skin forming and set aside.
• Remove the pastry from the fridge
• place the tin on a baking tray and bake for 15 minutes. Remove the baking beans and greaseproof paper. Brush the base well with beaten egg and bake for another 7–10 minutes
• or until the pastry is dry and pale golden-brown. Set aside to cool in the tin
• then using a sharp knife cut away the overhanging edge.
• For the Italian meringue
• add the sugar and 180ml/6¼fl oz water to a medium saucepan and bring to the boil.
• While the sugar and water is being heated
• use a paper towel to rub the inside of the bowl of a freestanding mixer with the lemon juice (this will remove any traces of grease that can cause meringues to fail). Add the egg whites to the bowl and whisk on a medium speed until stiff peaks form when the whisk is removed.
• Once the sugar syrup has reached 113C on a sugar thermometer
• remove it from the heat. With the motor running on the mixer
• pour the syrup slowly down the side of the bowl. Once the syrup has all been added
• increase the speed to high and whisk for about 7–9 minutes
• or until the bowl is cool to the touch and the meringue has stiff peaks.
• To assemble the tart
• remove the cling film on the curd and gently reheat
• if required. Once the curd is warm
• pour into the pastry case and smooth the surface.
• Spoon the meringue into a large piping bag fitted with a large open star nozzle. Pipe the meringue in swirls on top of the curd and then finish by browning the meringue with a chef’s blowtorch.
• Serve while the filling is still warm.