Preheat the oven to 350 degrees. Spoon the pumpkin puree into a food processor and add the eggs, cream, cheese, salt, and pepper. Process for 10 to 15 seconds to combine.

Coat a 6-cup gratin dish with the butter. Fill the dish with the pumpkin mixture. Sprinkle the Parmesan cheese on top and bake for about 35 to 45 minutes, or until set and lightly browned on top.

Raise the oven temp to 400 degrees. Prep a parchment lined baking sheet and place the puff pastry sheet/s on top*. Using a sharp knife, lightly score the pastry dough 1 inch in from the edges all around to mark a rectangle. (There is a link to a video to see how this is done (below this recipe card) if this does not make sense). Then, using a fork, pierce the dough all around in the center, not the edges. Next, you can use that same sharp knife to make slits on the edges if desired. Bake the pastry dough until golden, for about 15 minutes.

Remove the pastry shell from the oven, let it sit for a minute or two and then lightly drizzle on just a touch of extra virgin olive oil, spread on about 1 1/2 to 2 cups of pumpkin gratin and then sprinkle on the Swiss and Fontina cheese, using as much, or as little as you want. (I purposely used a little so you could see the pumpkin gratin on the tart).

Arrange the apple slices on top, lightly brush the apples with the melted butter and sprinkle on some turbinado sugar. Bake the tart for about 20 to 25 minutes, or until cooked though and nicely browned. Remove from oven and let cool for a few minutes. Slice, serve and enjoy immediately.