Preheat the oven to 200°C.
Blend the flour and butter together until the mixture looks like breadcrumbs.
Add the egg and milk and blend until a dough ball forms.
Knead the dough briefly and roll it out to the thickness of a coin.
Cut a 20cm rectangle, prick it with a fork, top with pear slices, and sprinkle with half the sugar.
Bake on a sheet for five minutes.
Add the remaining sugar and walnuts, then bake for three more minutes until golden.
Whisk cream, cocoa powder, and icing sugar in a saucepan over low heat to make the sauce.
Serve the tart slice with double cream and chocolate sauce drizzled over.