Preheat the oven to 400 degrees F. Place a piece of parchment paper on a sheet pan.

In a pan over medium high heat, add a little oil and then the shallots. Sprinkle lightly with salt and pepper. Saute until translucent and softened. Transfer to a bowl to cool.

Lay 1 sheet of puff pastry flat on a floured surface and carefully roll it out to 10 by 12 inches. It’s okay if it looks ugly and uneven at this stage. Transfer it to your sheet pan. Place a layer first of turkey, then cooled shallots, and then cheese, leaving a 1-inch border. Brush the border with the egg wash.

Place the second sheet of puff pastry on the floured board and roll it out to 10 by 12 inches. Place the second sheet on top of the filled pastry. Trim the edges straight with a sharp knife and press together with the tines of a fork. Brush the top with egg wash, then carefully cut a few slits in the top to allow steam to escape.

Bake for 25 to 30 minutes, or until puffed and golden brown. Check to see that the middle of the tart on the bottom is fully cooked too. The edges tend to cook faster. Allow to cool for a few minutes and serve hot or at room temperature.