250 g (9oz) plain flour, plus extra to dust
100 g (3 ½oz) caster sugar, plus 3tbsp extra
150 g (5oz) unsalted butter, chilled and cut into small pieces
1tsp ground cinnamon
1 egg yolk
700 g (1 ½lb) rhubarb, sliced into 2cm (3/4in) diagonal slices
1 tbsp vanilla extract
3 tbsp semolina
1 med egg, beaten
2 tbsp demerara sugar
Custard and ice- cream to serve
In a food processor, pulse the flour, 3tbsp sugar, butter and a large pinch of fine salt until the mixture resembles breadcrumbs. Or rub the flour, 3tbsp sugar, butter and pinch of salt together using a table knife until it forms pea-sized lumps, then continue to rub the mixture together with fingertips until it resembles breadcrumbs. In a bowl, beat together the egg yolk with 3tbsp ice-cold water. Gradually add the yolk mixture to the flour mixture, stirring it in quickly by hand or with the food processor motor running, until the mixture just comes together into large flakes without becoming sticky. Turn out the pastry on to a lightly floured surface and gently bring together with your hands, kneading briefly. Flatten to form a disc shape, then wrap in clingfilm and chill for 30 minutes.
In a large bowl, mix rhubarb with the remaining 100g (3½oz) sugar and set aside for 1 hour, stirring occasionally until juices are released from the fruit. Use a slotted spoon to lift the rhubarb out of the juice into another large mixing bowl and stir through the vanilla extract. Set juice aside for later.
Heat oven to 180°C (160°C fan) mark 4 with a flat baking tray inside to preheat. Lightly flour the work surface and a rolling pin and roll the pastry out into a circle about 35.5cm (14in) wide. Trim 1cm (½in) off the scraggy pastry edge to neaten. Use the rolling pin to lift the dough on to a large piece of baking parchment. Use a 20.5cm (8in) cake tin to gently press an indent in the centre of the pastry to mark out a circle. Evenly sprinkle semolina inside the circle and pile the rhubarb on top. Brush the 5cm (2in) pastry border with egg. Fold the border up and over the edge of the fruit, pinching a seam at 5cm (2in) intervals. Chill for 15min.
Brush pastry rim with remaining egg and sprinkle with demerara sugar. Carefully slide on to the preheated baking sheet and bake for 30-40min until golden.
Before serving, simmer the reserved rhubarb juice and 3tbsp water in a small pan for 3-4min until reduced to 1tbsp. Brush over the baked fruit to glaze.
Serve warm, with custard & ice-cream or just custard or just ice-cream but I love both! I also love this pie cold with a cup of tea for breakfast the next day.