First, make the pastry. Measure the flour into a large bowl before cutting the butter into cubes. Using the tips of your fingers, rub the butter into the flour to form a breadcrumb texture. Sieve in the icing sugar and stir through.

Add the egg yolk and water and bring the mixture together to form a soft dough. Wrap in clingfilm and place in the fridge to chill for 30 minutes.

Preheat the oven to 180˚C/ Fan 160˚C/ Gas Mark 5. Remove the pastry from the fridge and allow to soften slightly. Roll out the pastry on a floured surface just bigger than casserole. Lightly grease the dish with a little butter and lay in the rolled-out pastry. Allow the pastry to overhang the edges of the casserole and trim off the excessive pastry - reserve for decoration.

Prick the pastry with a fork and line with parchment paper and fill with the ceramic baking beans. Bake for 20 minutes, then remove the baking beans and return to the oven for a further 5 minutes until the pastry is golden.

Combine the fruit filling ingredients in a large bowl before spooning into the baked pastry case, before making the topping.

Sieve the flour into a large bowl and rub the butter in using your finger tips to form breadcrumbs. Stir through the sugar. Blitz the hazelnuts in a food processor until finely chopped before adding to the crumble mixture.

Sprinkle the crumble topping over the fruit evenly. With the pastry off-cuts, make pretty floral pie toppers. Bake in the oven for 30 minutes until the crumble topping is golden and the fruit bubbling.

Serve with ice cream, cream or custard.

Cook's Notes If you can't get hold of fresh fruit, frozen fruit will work well too. Ensure the fruit is defrosted in a colander to remove excess liquid and add an extra tablespoon of corn flour to soak up any extra moisture.