Serves 6
225g shortcrust pastry (flour weight, see Cook now recipe index)
Rhubarb curd filling
1 kg rhubarb (prepared weight)
200g caster sugar
60g cornflour
45g butter
3 medium egg yolks, strained
Meringue topping
3 medium egg whites
170g caster sugar
Slice the trimmed rhubarb into small chunks. Put in a non-corrosive saucepan with 3 tablespoons water. Cover and set over a low heat. Once the rhubarb begins to release some juice, increase the heat and simmer for 10 minutes or until it has disintegrated. Tip into a fine sieve and leave to drip into a bowl. Measure out 450-500ml rhubarb juice.
Preheat the oven to 200°C/gas 6. On a clean, lightly floured surface, roll out the pastry until it forms a sheet large enough to line a 23cm diameter tart case with a removable base. Prick the bottom with a fork, line with greaseproof paper and fill with baking beans. Chill for 30 minutes.
Bake the tart in the centre of the preheated oven for 15 minutes. Remove the covering and continue to bake for another 5 minutes, or until the pastry has become dry, but not coloured. Remove and reduce the oven temperature to 150°C/gas 2.
Place the cornflour and sugar in a small non-corrosive saucepan. Using a wooden spoon, slowly stir in the rhubarb juice so that it forms a smooth paste. Set over a medium heat and stir continuously for 5 minutes or until the bubbling mixture has thickened and become translucent. If it still tastes of cornflour, cook for a little longer. Remove from the heat, beat in the butter, followed by the egg yolks.
Spoon the mixture into the pastry case. Immediately whisk the egg whites in a clean bowl until they start to form soft peaks. Add half the caster sugar and continue to whisk, gradually adding the remaining sugar. Continue to whisk until it forms a soft glossy peaks. Gently spread the meringue over the tart, so that it touches the pastry rim and seals in the rhubarb curd.
Return the pie to the oven and bake for 30 minutes or until the meringue has set with a crisp, lightly browned crust. The curd becomes firmer as it cools. Once cool, remove from the tart case and transfer to a serving plate. If serving the next day, store uncovered on the top shelf of the fridge.
