Preheat the oven to 400�F.
Saut� minced shallots and butter in medium sized saut� pan on medium-high for about two minutes, until brown and crisp.
Add the mushrooms and olive oil. Saut� on medium, stirring occasionally, for about 10 minutes until lightly browned and mostly dry. Remove from the heat and allow to cool.
Line a baking sheet with parchment paper. Lightly flour the paper. Unfold the dough onto the baking sheet, gently straighten and make even.
Using the tip of a knife, gently score a 1 inch square border on the pastry sheet without cutting all the way through.
Using a fork, pierce the dough inside the square frame (not the border), in multiple spots.
Using a pastry brush, brush entire top of pastry with egg to add a nice sheen to the crust and to create a moisture barrier for the other ingredients.
Bake the tart for 15 minutes in the center of the oven. Remove from oven and use a fork to gently flatten down any puffed areas.
Spread saut�ed mushrooms and chopped Truffle Tremor� evenly across the sheet and bake for an additional 10 minutes. If the pastry begins to look too brown, add a foil tent over just the crust area of the puff pastry.
Remove from oven, sprinkle with fresh thyme leaves. Add a light dusting of freshly grated nutmeg, if desired. Serve warm.