Preheat oven to 180°C. Cream the butter and sugar in a bowl using a wooden spoon, or blitz them together in a food processor. Beat in the eggs, one at a time - the mixture may look like it has curdled, but don’t worry, it’ll come together. Sieve the flour, ginger and salt and stir this in. Mix in the vanilla. Reserve 12 walnut halves, finely chop the remainder and mix these in, then tip the filling into the uncooked tart shell and press it flat. Cut the figs in half lengthways and press them into the mixture then tuck the reserved walnut halves, which you’ve broken into two, in as well. Sprinkle the reserved sugar over the fig cavities.
Place the tart on a baking tray and bake in the lower centre of the oven for 50 minutes. The tart is ready when the rim of the pastry has turned the colour in the photograph. If for some reason your tart filling or fruit looks like it’s burning, then place a sheet of foil, the same size as the tart, on top.
Take from the oven and leave to cool on a cake rack before removing from the tin.