Created by TxGriffLover on October 24, 2011
Step 1: To prepare mushrooms, heat butter and oil in a large heavy bottomed skillet over medium heat until shimmering.
Step 2: Add the mushrooms and saute until soft and all the liquid in the pan has evaporated, about 5 minutes.
Step 3: Add the shallot and cook until translucent, about 5 minutes more, then add the herbs and nutmeg.
Step 4: Taste and adjust for seasoning with salt & pepper and set aside to cool.
Step 5: Line a baking sheet with a silicone baking sheet or parchment paper.
Step 6: In a small bowl, whisk together the egg and water to make a wash and set aside.
Step 7: To prepare the pastry, on a lightly floured surface, roll out the puff pastry to a 12 x 13 inch rectangle.
Step 8: From it, but one 12 x 5 inch rectangle, two 11 x 1/2-inch strips and two 5 x 1/2-inch strips.
Step 9: Place the rectangle on the prepared baking sheet and prick all over with a fork and brush all the pastry strips with the egg wash.
Step 10: To form the pastry shell, place the short pastry strips, egg-wash side down, along the edged of the short sides of the pastry; place the long strips, egg-wash side down along the edges of the long sides of the pastry. (Don't worry about making all of this very exact: the goal is to create a rim to contain the mushrooms).
Step 11: For a more rustic look, leave the 12 x 15 rectangle intact, and simply create a rim by folding over all 4 edges, and seal with egg-wash.
Step 12: Chill until firm, about 10 minutes in the freezer or 50 minutes in the refrigerator.
Step 13: Preheat oven to 400ยบ and bake the tart shell until golden, about 15 minutes.
Step 14: Remove from the oven and spread the cheese evenly over bottom of the hot shell.
Step 15: Top with the reserved sauteed mushrooms.
Step 16: Return to the oven and continue to bake until heated through, about 10 minutes.
Step 17: Remove from the oven and let cool slightly.
Step 18: Cut into strips and serve.