Heat the oven to 200C/180C fan/gas 6 with a large baking sheet inside to heat up. Roll the pastry out on a lightly floured surface to a 5mm thickness. Cut out a 30cm circle, then score a smaller circle, around 10cm in diameter, in the centre of the pastry circle. From the centre of the inner circle, cut eight triangles that end at the scored line, being careful not to cut them out completely. Transfer the pastry circle to a sheet of parchment.

Stir the cranberry sauce to loosen it, then spread it over the larger outer circle of the pastry, in between the scored edge and outer edge. Slice the brie into 1cm-thick rectangles, then arrange in a line on top of the cranberry sauce, leaving a 5cm border around the edge. Sprinkle the hazelnuts over the brie.

Fold the outside edge of the pastry halfway over the brie, then brush with some of the beaten egg. Bring the point of each cut triangle over to meet the folded-in edge. (See tip, below, for using any pastry offcuts.) Brush all the pastry with the beaten egg and sprinkle over the mixed herbs. Carefully slide the wreath onto the hot baking sheet in the oven, and bake for 20-25 mins until the wreath is golden brown and the brie has melted. Leave to cool for 5-10 mins, then garnish with micro herbs or salad leaves, if you like, and serve.