- 125 g (4 oz) plain flour, plus extra for dusting
- 50 g (2 oz) butter, chilled and diced
- 25 g (1 oz) caster sugar
- 1 small egg, beaten
- icing sugar, for dusting
For the filling
- 75 g (3 oz) plain chocolate, broken into pieces
- 1 tablespoon water
- 5 g (1⁄4 oz) unsalted butter
- 1 teaspoon brandy or Cointreau
- 2 small eggs, separated
Sift the flour into a bowl. Add the butter and rub in with your fingertips until the mixture resembles fine breadcrumbs. Stir in the caster sugar, then add the egg and mix to a firm dough, adding a little iced water if necessary.
Turn the dough out on a lightly floured surface and knead briefly. Roll out and use to line four deep 7.5 cm (3 inch) tartlet tins. Re-roll the trimmings and line 2 more tartlet tins. Press a square of foil into each and place the tins on a baking sheet. Bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 15 minutes. Remove the foil and bake the tartlet cases for a further 5 minutes. Leave to cool.
To make the filling, put the chocolate with the water in a heatproof bowl set over a saucepan of barely simmering water so that the base of the bowl is not touching the water and leave until melted, stirring occasionally.
Remove the bowl from the pan and stir in the butter until it has melted. Add the brandy or Cointreau and stir in the egg yolks.Whisk the egg whites in a grease-free bowl until they are stiff and dry. Using a large metal spoon, fold the egg whites into the chocolate mixture.
Spoon the mousse mixture into the tartlet cases, then transfer to the refrigerator for 2–3 hours until set. Dust the tartlets lightly with icing sugar before serving. Serve cold.