In the food processor, pulse the flour, icing sugar and butter to reach a texture like breadcrumbs. Tip into a large mixing bowl and add the egg yolk stirring until ingredients come together in large clumps. If necessary, add a few drops of water to bring together into a ball.

Shape the dough into a flat disc, wrap in cling film and chill for 20 minutes - too long and it will be tricky to roll out. Whilst chilling, preheat the oven to 220c / gas 7.

Roll the pastry on a lightly floured surface and line the tart tin carefully pushing into the corners without tearing. Bake for 10-15 minutes until golden. Reduce the oven temperature to 180c /gas 4.

In a small saucepan heat the membrillo with the water and orange juice over a low heat until it becomes jam-like and free of lumps. Spread evenly on the base of the pastry case.

Meanwhile, pulse the almonds in the food processor until they are in medium chunks (tip: retain a small handful to drop in at last few pulses so some stay bigger). Tip the nuts into medium size bowl and combine with the orange zest, cinnamon and amaretto.

Meanwhile, using an electric mixer with a large bowl, beat the eggs and sugar together until fluffy then add the eggs as if making a sponge cake.

Fold in the nut mixture and when combined, spoon into the pastry case and spread towards the edges with a silicon spatula.

Bake in the centre of the oven for 30 minutes until golden. Leave to cool in the tin for a few minutes before turning out onto a wire cooling rack to cool completely.