Put the figs and half of the sherry in a microwave-proof bowl (or pot on the stove top) and gently heat to a simmer.
Remove from the heat and allow to cool.
Put the figs, soaking liquid and crystallized ginger in a small food processor and whiz to form a chunky paste.
Put the chocolate, cream and butter in a large heatproof bowl and melt together over a pot of simmering water, ensuring the base of the bowl doesn't touch the water.
Stir occasionally and once the chocolate has melted add the golden syrup and second measure of port or sherry and whisk to combine.
Spread the fig paste evenly into the base of the tart pastry shell.
Pour in the chocolate mixture and leave to set, un-refrigerated, for six hours or overnight.
Serve with chocolate ginger cream.