Cut the sheet of puff pastry in a circle to fit an ovenproof frypan. Preheat the oven to 180 degrees C.
In a mixing bowl, toss the apple slices with the nutmeg, cinnamon, lemon juice and 2 tablespoons sugar.
Heat the 1/3 cup sugar in the frypan over medium high heat until it melts, but don't let it burn. Cook until just golden then remove from the heat.
Add the apple slices in the pan in rings, starting from the outer edge, overlapping each slice slightly. Place the puff pastry over the top and tuck in the edges with a butterknife.
Bake 30 minutes or until pastry is golden.
Cover the tart with a large plate and invert the pan so the tart drops onto the plate. If the caramel is sticking, you can heat it for a few moments on the stovetop and try again.