Patrick’s Chocolate Mousse Tart

PASTRY: Whizz the flour, cocoa, sugar and butter in a food processor to form "breadcrumbs". Add the water and pulse just until clumps form. Tip onto the bench and squash together, then pat into a round. Chill for 15 minutes, then roll out between two sheets of baking paper into a circle slightly larger than your tin. Remove the top layer of baking paper and invert into the tin. Press in and trim the edges. Chill for 15 minutes.

Preheat the oven to 180°C fan bake.

Line the pastry shell with baking paper, fill with baking beans or rice and bake for 12 minutes. Remove the beans and paper and bake for a further 10 minutes, until lightly crisp. Cool in the tin.

FILLING: Melt the chocolate and 100ml of the cream together in a heatproof bowl over a pot of simmering water, stirring until smooth. Don't let the bowl touch the water. Whisk the egg yolk with the Kahlua, then whisk into the chocolateoff the heat. Beat the egg whites to medium peaks. Whip the remaining 200ml cream to soft peaks. Fold a third of the egg whites into the chocolate mixture, then add the remaining egg whites and whipped cream and whisk together until smooth. Pour into the cooled tart shell and chill for at least 3 hours before serving. Let sit at room temperature for 5 minutes, then dust with cocoa to serve.