Peel the pears, cut them in 2, then core them.
Bring the water with the sugar to a boil, add a vanilla pod split in 2 and the lemon juice. Poach the pears over a low heat with a lid on for 20 minutes.
Drain the pears and let them cool. Thinly slice them.
Prepare a sabayon by whipping the double cream into a chantilly with 30 g of icing sugar. In a bowl, whisk the egg yolks with the caster sugar until the mixture becomes pale and fluffy, then add the pistachio paste.
Delicately mix the egg yolk and sugar mixture with the chantilly cream.
Arrange the pears in a deep plate, drizzle with crème de cassis and cover with the pistachio sabayon. Sprinkle with icing sugar then caramelize with a blowtorch.
«If you want an alcohol free recipe replace the crème de cassis with blackcurrant cordial.»