Preheat the oven to 190°C.
Cream the fat, Hermesetas Granulated and egg yolk together and then gradually work in the flour adding the water, if necessary, to make a soft but not sticky dough. Use the pastry to line a shallow 23 cm flan tin. Chill until required.
Peel, core and thinly slice the apples then arrange them overlapping, in layers in the flan case sprinkling Hermesetas Granulated between each layer. Bake the tart for 30-40 minutes until the apples are tinged golden brown and the pastry cooked. Leave to cool slightly and then brush the surface with apricot jam.