Zest the orange into a small bowl and put to one side. Squeeze the juice into a medium pan and add the sugar or honey, ginger and about 400ml water. Bring to a simmer and add the pears, adding more hot water, if needed, to cover them.
Return to a simmer and cook for three to five minutes, until they are only just tender but the tip of a knife can be inserted easily. Cooking time will depend on their ripeness, but you want them to hold their shape.
Once cooked, transfer the pears to the bowl of orange zest. Reduce the pear liquid in the pan for 15-20 minutes until it is a syrup, pour this over the pears and leave to cool.
Next, make the custard. In a large bowl, use an electric whisk to beat the egg yolks with the sugar for about five minutes, until thick and pale. Whisk in the mascarpone a bit at a time, trying to avoid any lumps, then mix in the sherry or marsala.
In a clean bowl, whisk the three egg whites to stiff peaks. Stir a big tablespoon of this into the mascarpone mix, then gently fold in the rest, being careful not to over mix. Transfer to the fridge for a moment.
When the pears are cool, spoon them into a large, glass bowl and spoon over enough poaching syrup just to cover. Sprinkle over a third of the chocolate, then lay the panettone slices on top.
Drizzle with the sherry or marsala and a few teaspoons more of the syrup, followed by another third of the chocolate and the mascarpone custard. Refrigerate for at least three hours.
When you are ready to serve, scatter over the last of the chocolate, the flaked almonds and crystallised ginger, then serve as a festive dessert .