Preheat an oven to 180 degrees Celsius fan/gas 4. Spread the pistachio nuts on a baking tray and place in the oven for five minutes to roast; allow them to cool for five minutes and then chop them.

Roll out the puff pastry to a 20x30cm rectangle on a surface lightly dusted with flour. Line a baking sheet with parchment paper, and brush with half the melted butter to form a rectangle the same size as your pastry.

Sprinkle that zone with half the brown sugar. Place the pastry exactly on top of the buttered and sugared area.

To make the frangipane whisk together the 50g butter and 50g caster sugar until pale, then slowly add the egg, then mix in the ground almonds.

Evenly spread the frangipane onto the pastry, leaving a one centimetre border. Refrigerate for 10 minutes to harden up slightly.

Cut the pears in half, scoop out the core and pips with a teaspoon or melon baller then cut into slices. Neatly lay overlapping pear slices on top of the filling in either two or three long lines, alternating directions to create a wave-like pattern.

Brush the top of the pears with the remaining melted butter and sprinkle with the remaining sugar. Lastly, brush the edges of the pastry with beaten egg, sprinkle with pistachios. Bake for 25-30 minutes, or until the pastry is risen and golden.