Taleggio cheese has great melting qualities, and its mild creaminess pairs beautifully with thyme. I like the freeform shape of a galette: it also means you don’t need a specific tart tin to make it. I use half wholemeal and half plain flour to give the pastry extra flavour and texture.
For the pastryplain white flour 140gwholemeal flour 140gunsalted butter 170g, very cold and cut into cubesflaked salt a large pinchiced water 4-5 tbspegg 1, beaten for egg wash
For the fillingbutter 25golive oil 2 tbspleeks 4 medium, about 600gthyme a few sprigs, leaves picked from the stalkscreme fraiche 2 tbsppotatoes 400g, skin on, very thinly sliced (2mm)taleggio 270g, rind removed
Make the pastry: put the flours, butter and salt into a food processor and blitz briefly, until the butter pieces are the size of petit pois. Tip into a bowl and add the water, 2 tablespoons at a time, mixing by hand to bring the mixture together. Roll the dough into a ball and squash to a thick disc, wrap with clingfilm and refrigerate for at least 20 minutes.
Meanwhile, melt the butter and oil in a large saucepan over medium heat. Add the leeks and thyme, season well and cook, stirring for at least 20 minutes until very soft and sweet…