Sift the flour and sugar into a bowl and rub in the fat spread until the mixture resembles breadcrumbs. Stir in the egg white to make a slightly soft, but not sticky, pastry.
Put the pastry onto a lightly floured surface and knead for a few seconds until it is smooth. Roll out thinly into a 23 cm (9 in) round. Use the pastry to line a 20 cm (8 in) round tart tin with a removable base, pressing down firmly. Trim the edges, then lightly prick the base with a fork. Put the pastry case into the refrigerator to chill for at least 30 minutes.
Meanwhile, make the filling. Peel and cut the apples into quarters, then core and cut them into 1cm (½ in) slices. Put the apples into a nonstick saucepan, stir in 50 g (1¾ oz) of the sugar, the lemon zest and juice and 1 tablespoon of water. Cover and simmer over a medium-low heat for 10-15 minutes, stirring occasionally, until the apples are just soft and fluffy, but still retain some texture.
Halve and stone the plums. Pour 150 ml (5 fl oz) of water into a large frying pan over a high heat, stir in the remaining sugar and bring to the boil, stirring continuously. Reduce the heat to medium, place the plums in a single layer in the syrup and poach for 15 minutes, turning them over halfway through, until they are soft when pricked with a knife.
Spoon the apples into a sieve and leave them to drain. Using a slotted spoon, transfer the plums to a plate. Bring the plum liquid to the boil and continue boiling until it has reduced to a thick syrup. Pour the syrup over the plums and set aside to cool.
Meanwhile, heat the oven to 220°C (425°F, gas mark 7) and place a baking sheet in the centre to warm.
Line the chilled pastry case with foil, weigh down with baking beans, place it on the hot baking sheet and bake for 15 minutes. Remove the foil and bake the pastry for a further 5-10 minutes until it is golden brown and cooked through.
Spoon the apples into the pastry case, spreading them out evenly, then arrange the plums on top. Set aside.
To make the meringue, put the egg whites into a clean bowl and whisk until they form soft peaks. Add the caster sugar 1 tablespoon at a time, whisking well between each addition, until the meringue is stiff and shiny.
Spoon the meringue on top of the pie and spread it evenly over the plums, then make large peaks in it with a palette knife.
Bake the tart for 4-5 minutes until the meringue is golden brown. Leave it to set for 1-2 minutes, then remove it from the tin. Serve the tart warm or at room temperature.
I tried this out when we had friends coming round for an informal dinner. The pastry was very quick and easy to make and rolled out successfully. I only had butter, not 70% fat spread and it turned out well. The apples cooked much quicker than the recipe suggests but I caught them before they completely disintegrated and I couldn't managed to whisk the meringue to a very stiff consistency, but that didn't really matter. The overall effect was a pudding that looked pretty in a homely sort of way, tasted delicious and had a lovely crisp pastry. My only criticism is that it's quite time consuming to prepare, with so many different stages needed. - 28 Sep 2011