2) Lay the sheet of puff pastry on a work surface, brush with melted butter and sprinkle with half the cinnamon sugar. Cut into 6 even pieces.
3) Keeping the stem end attached, cut the pears into 1/2cm thick slices. Fan the pear slices over the puff pastry, using 1/2 a pear for each puff pastry square. Sprinkle the the pear tarts with the remaining cinnamon sugar mixture.
4) Bake until the pastry is golden and cooked through, about 20 to 25 minutes. Remove the tarts from the oven, sprinkle with the cheese and bake until the cheese melts, 5 minutes more.