Start by prepping the pears: melt butter with sugar in a large pan and add nutmeg, thyme and a pinch of salt. Add the slices of pears and cook for a few minutes on each side.
Take the puff pastry sheet out of the fridge and use a small knife (spine side) to score the border about 1.5cm from the edge. Brush the border with the beaten egg.
Arrange the pear slices on top and brush with the liquid left from cooking. Bake at 170C for 20-25 minutes.
Take the tart out of the oven and place a few dollops of Gorgonzola here and there. Place back into the oven for a couple of minutes until the cheese melts.
Scatter over candied pecans and a few dried barberries if desired.
Serve warm or at a room temperature.
Notes
This tart can be refrigerated for a day but is best consumed fresh.