Line a 450g loaf tin with a double layer of cling film, so that the entire inside of the tin is lined and the excess hangs over the sides.

Add the pistachios and chocolate to the bowl of a food processor and briefly pulse until they resemble coarse breadcrumbs.

Put the egg yolks and sugar in a large bowl, place over a pan of simmering water and whisk constantly until thick and pale, 2–3 minutes.

Remove the bowl from the heat and whisk through the mascarpone, pistachio cream and vanilla. Set aside.

In a separate bowl, whisk the egg whites and the salt until the meringue holds soft peaks.

Add the cream to a large bowl and whisk until it holds soft peaks.

Add the whipped cream to the mascarpone mixture and fold together.

Fold the meringue through the mascarpone cream mixture in three additions, trying to keep it as light as possible.

Pour the coffee and amaretto into a shallow bowl.

Sprinkle a third of the pistachio/chocolate mixture into the bottom of the loaf tin.

Spread a thin layer of the mascarpone cream atop the pistachio layer, then add a layer of sponge fingers, dipping them briefly into the coffee mixture first.

Spoon just under half of the remaining cream atop the sponge finger layer and spread into an even layer.

Repeat the layering of pistachios/sponge fingers/cream a second time.

Finish by spreading the last portion of cream on top and sprinkling over the final third of the pistachio mixture.

Wrap the tiramisu with the overhanging cling film, so that it is fully sealed in the tin.

Refrigerate for at least 4 hours.

To serve, unwrap the top layer of cling film so the base of the tiramisu is exposed.

Carefully invert the tiramisu onto a serving platter and peel away the remaining cling film.