1 Preheat oven to 180°C/350°F; make rhubarb and pear filling. Place rhubarb, pear and sugar in an ovenproof dish; roast for 30 minutes. Transfer rhubarb mixture to a medium saucepan; cook, stirring, over high heat for 5 minutes or until thick. Cool. Stir in ginger and vanilla. Cover; refrigerate until required.

Meanwhile, in this order, place flour, sugar and butter in a food processor (butter should not be on the base). Pulse a few times until mixture resembles coarse crumbs. Add egg yolk and 1½ tablespoons of the beaten egg; pulse until ingredients just come together. Reserve remaining beaten egg. Knead pastry gently on a lightly floured surface. Divide pastry in half; flatten rounds into discs. Wrap in plastic wrap; refrigerate for 30 minutes.

Lightly grease a 24cm (9½in) round loose-based tart tin. Roll out one portion of pastry between sheets of baking paper until large enough to line tin. Ease pastry into base and side; trim edge. Prick base all over with a fork. Cover; freeze for 10 minutes.

Roll remaining pastry to a 26cm (10½in) round. Place on a tray; cover, refrigerate until required.

Preheat oven to 180°C/350°F. Place tin on an oven tray; line pastry with baking paper, fill with dried beans or rice. Bake pastry for 10 minutes. Carefully remove paper and beans; bake for a further 10 minutes or until golden brown.

Spoon rhubarb filling into pastry case. Lightly brush edge of the baked pastry case with a little of the remaining beaten egg. Cut rolled pastry into 1.5cm (¾in) strips. Place strips on top of filling, weaving as you go, to form a lattice pattern; trim ends. Brush pastry with a little more beaten egg; sprinkle pie with demerara sugar. Return pie to oven tray.

Bake pie on the top oven shelf for 25 minutes or until pastry is golden and crisp. Leave pie on tray for 20 minutes; transfer to a wire rack to cool.

Rhubarb and pear filling can be made up to 2 days ahead; keep refrigerated. Pastry can be made a day ahead; keep refrigerated.Serve with vanilla crème anglaise.