Warm Crumble Tart

Preheat the oven to 200'c, gas mark 6. Place a baking sheet in the top half of the oven to heat up.

For the pastry, put the flour and butter in a food processor and pulse until it looks like fine breadcrumbs (or do this manually using fingertips). Add the sugar and pulse a couple of times to distribute. Then add the egg yolk and 2 tbsp ice-cold water. Pulse until pastry just comes together to form a dough. Careful not to over process.

Turn the dough onto a lightly floured surface. Roll out the dough to form a circle that is large enough to cover the base and sides of the tart case with some overhang. Roll the pastry over your pin and gently lay over the case. Gently press into the base and up the sides, allowing the excess to fall over the edges. Roll the pin over the top to cut away the excess, prick all over the base with a fork, then pop in the freezer for 15 minutes or the fridge for 30 minutes.

When ready to bake, line with parchment and baking beans. Bake for 10-15 minutes until the sides are just turning golden. Remove the parchment and beans and bake for another 10-15 minutes until light golden all over. Lightly beat the egg white and, as soon as the case comes out of the oven, brush over the base and sides to help seal the pastry and prevent it going soggy when you add the filling. Cool completely.

For the filling, in a large lidded saute or frying pan, heat the butter until fairly hot and starting to brown. Toss in the apple and fry for 30 seconds or until starting to brown. Toss 100g of the sugar together with the apple over a medium-high heat, then reduce to low and add 2 tbsp water. Cover with a lid and gently steam for about 3-4 minutes until just soft. Take off the heat and stir in the blackberries, and leave covered for a few more minutes. Check for sweetness, adding a little extra sugar if needed. Uncover to cool completely.

For the crumble, place the flour and butter in the food processor and pulse to fine breadcrumbs. Pulse in the sugar once or twice, then tip into a large bowl and work with fingertips to make larger crumbs.

Strain the fruit filling over a bowl and catch the juices. Spoon the fruit into the baked, filling to 3/4 of the way up. Keep any leftover and puree with the juices to serve as a coulis over the pudding. Sprinkle an even layer of crumble over the fruit, then bake for 25-30 minutes golden. Cool for 5 minutes before serving.

Meanwhile, make the custard. In a large bowl, whisk together the sugar, cornflour, egg yolks and vanilla bean paste until smooth. Place the milk and cream in a large heavy-based saucepan and bring to the boil. Take off the heat and slowly pour in a fine sieve over the egg yolk mix, whisking constantly to combine.

Rinse out the pan, then pour the custard back in. Gently heat, stirring for about 5-8 minutes, or until thickened. Serve with the tart. (If not using immediately, cool the pan in a bowl of cold water. Cover the surface of the custard with a piece of damp parchment. Gently reheat, but don't boil).