Preheat the oven to 180ºC.
Check that you have 5 pear halves of even size from the tin.
Unroll the pastry and put the upturned 24cm frying pan onto the pastry, and use this as a rough guide to cut out a circle of pastry. (Don’t worry if the frying pan hangs over the edge of the pastry, it is only a guide.)
Reserve the pastry on a flat tray lined with baking parchment in the fridge.
In the 24cm frying pan pour in the olive oil, then arrange the shallot and pear halves alternately, cut-side down, so the points of the pears face the centre of the pan (you might need to trim the shallots to make them fit).
Place the pan on a medium heat and slowly caramelize the pears and shallots. This should take about 12 minutes.
Check them occasionally to make sure they are colouring evenly.
Once they are golden, remove the pan from the heat and add the butter.
In a small bowl, take 80g of the Saint Agur creme and reserve. Remove the pastry from the fridge and evenly spread the remaining 70g of the Saint Agur Blue Cheese Crème over the top.
Lay this into the frying pan with the cheese side facing up, using your fingertips or the handle of a dessert spoon to push the edges of the pastry down to surround the caramelised pears and shallots.
Bake for 30-35 minutes, until the pastry is golden all over.
Leave the tart to cool slightly and then run a knife blade around the pan’s edge to release the pastry.
Place a large serving plate on the top of the frying pan upside down, and in one swift movement turn the pan and plate so that – et voila – the tart is now on the plate. (Careful not to burn yourself).
Using a teaspoon, spoon drops of the reserved Saint Agur Creme over the tart, serve warm to your guests.