Return the batter to room temperature before cooking, adding a splash of water, if necessary, to produce a batter the consistency of single cream.
Meanwhile, prepare the figs. Melt the butter in a frying pan and when foaming, add the figs, cut-side down. Cook for one minute or so, or until caramelised, then flip onto the other cut side and cook for a further minute. Transfer to a plate and set aside.
Heat a non-stick frying pan or crêpe pan over a medium heat and brush with butter or oil. Pour 60ml batter into the pan and quickly swirl to cover the base. Cook for one to two minutes, or until golden underneath. Flip and cook for a further 30 seconds to one minute. Repeat with the remaining batter.
Preheat the grill to high and line a baking sheet with baking paper.
Lay a galette flat on a chopping board and arrange four fig quarters on the bottom half. Break or cut one-eighth of the Gorgonzola into small pieces and dot them around the figs. Scatter over one-eighth of the walnuts.
Fold the galette over into a half-moon shape and in half again to make a triangle. Transfer to the prepared baking sheet and brush the top with a little melted butter. Repeat with the remaining galettes and fillings.