Heat the oven to 190C/Gas5; roll out the pastry to about 2mm thickness and use to line a deep 24cm diameter tart tin, leaving the excess pastry overhanging the edge of the tin; place the pastry-lined tin in the freezer for 10 minutes, then bake blind for 20 minutes; remove the baking beans and paper and bake for a further 10 minutes; remove from the oven and leave to cool; lower the oven temperature to 140C/Gas1; when the pastry case is cool, use a knife to carefully trim the pastry from the edge
Put the citrus zests and juices in a saucepan with the rosemary, golden syrup, maple syrup, butter and salt and bring to the boil; remove from the heat, pour into a large shallow bowl and leave to cool; remove and discard the rosemary sprigs
Mix together the citrus syrup with the breadcrumbs and leave to stand for 5 minutes so the breadcrumbs absorb some of the syrup; mix in the egg and egg yolk, then spoon the mixture into the pastry case and bake for 50-60 minutes until it is set but still has a bit of a wobble in the centre; remove from the oven and leave to cool for at least 10 minutes before serving with crème fraiche
10 servings