Preheat your oven to 300 degrees F and line a baking sheet with a sheet of waxed paper.
Put your egg whites into a squeaky clean bowl, making sure there are absolutely no little pieces of egg shell or egg yolk in them. Whisk on medium until the whites form firm peaks. With your mixer still running, gradually add the sugar and the pinch of salt. Turn the mixer up to the highest setting and whisk for about 7 or 8 minutes, until the meringue mixture is white and glossy. To test whether it's done you can pinch some between your fingers - if it feels completely smooth it's ready; if it's slightly granular it needs a little more whisking.
Dot each corner of the waxed paper with a blob of meringue, then turn it over and stick it to the baking sheet. Spoon the meringue out onto the paper. Using the back of a spoon, shape and swirl it into a rectangle. Place in the preheated oven and bake for 1 hour or until crisp on the outside and a little soft and sticky inside. At the same time, bake the hazelnuts on a separate sheet in the oven for 1 hour or until golden brown.
Drain the cans of pears, reserving the syrup from 1 can. Cut each pear half into 3 slices. Pour the pear syrup into a saucepan with the ginger, if using, and warm gently over a medium heat until it starts to simmer. Take off the heat and snap the chocolate into the saucepan, stirring with a spoon until it's all melted.
Take the meringue and hazelnuts out of the oven and leave to cool. Place the meringue on a nice rustic board or platter. Whip the cream with the sifted icing sugar and the vanilla seeds until it forms smooth, soft peaks. Smash the toasted hazelnuts (in a kitchen towel) and sprinkle half of them over the top of the meringue. Spoon half the whipped cream over the top and drizzle with some of the chocolate sauce (if the sauce has firmed up, melt it slightly by holding the saucepan over a large pan of boiling water). Divide most of the pear pieces evenly over the top. Pile over the rest of the whipped cream and pears. Drizzle with some more chocolate sauce, then sprinkle over the remaining toasted hazelnuts with some grated orange zest. Serve straightaway. If you're making this in advance, get everything ready and assemble at the last minute.
This recipe has been updated and may differ from what was originally published or broadcast.
Recipe Excerpted from JAMIE AT HOME by Jamie Oliver. Copyright (c) 2008. Published in the U.S. by Hyperion. All Rights Reserved. www.jamieoliver.com