Created by Kchurchill5 on February 19, 2016
Step 1: Mushrooms ... First, what mushrooms to use. You can really use any mix that you like; but, I basically try to use what is in season, and what you like. Make sure the mushroom stems are trimmed; and, note ... shitake mushrooms stems tend to be very tough; so, I usually save those for a stock later on. Again, there is no right or wrong; use what is available, and what you like.
Step 2: Pastry ... Remove the pastry from the freezer to the refrigerator to thaw. I like to let it thaw all day if possible. Then, as you cook the mushrooms; transfer the thawed pastry to a cutting board or counter, lightly dusted with flour. Press the seams together; and roll it out to create a smooth sheet of pastry. Next, cut the pastry in half (on the long side); creating 2 rectangles.
Step 3: Transfer the to pieces to a baking sheet, lined with parchment paper. Then, to make a crust for the tart; fold all 4 sides/edges over 1/2". When baked, the sides will 'puff' up doubling in size, creating a crust for the tart. Poke or prick the bottom of each pastry with a fork; then, brush with the mustard, and sprinkle with the parmesan cheese.
Step 4: Mushrooms ... Add 3 tablespoons butter to a large saute pan (non-stick preferred) over medium-high heat. Add the leeks, shallots, mushrooms, and herbs; and, saute 3-4 minutes stirring often. Then, reduce the heat to medium - add the garlic, salt and pepper; and, saute another couple of minutes. Add the marsala wine, mix; and, continue to cook until golden brown and all the liquid is gone, 3-4 minutes. Remove from the heat to cool.
Step 5: Bake ... Preheat oven to 400 degrees. Fill the pastry with the slightly cooled mushroom mix, brush the edges of the pastry with the beaten egg; and, bake for 16-20 minutes on the middle shelf until golden brown.
Step 6: Serve and ENJOY! ... Now, I like to garnish with a little fresh parsley; then, cut it and serve as is. But, a friend of mine loves to top it with herbed goat cheese, which is optional - but, very good. Simply crumble the cheese on top while it is still warm. This can be served as an appetizer, a snack, lunch; or light dinner, served with a bowl of soup.