Mushroom Onion Gruyere Tart - cooking recipe

Ingredients

1 tablespoon canola oil
1 tablespoon butter
1 sweet onion (sliced)
1 lb mushroom (sliced)
salt (to taste)
pepper (to taste)
1 sheet puff pastry (defrosted)
2 -3 tablespoons honey mustard
3/4 cup gruyere cheese
1 tablespoon milk
1 egg

Preparation

Preheat oven to 450 degrees F.
Line a cookie sheet with a sheet of bakers parchment paper.
Place a sheet of puffed pastry flat on parchment.
In skillet over medium low heat add olive oil and butter.
Saute onion for 15 minutes or until translucent. Stir frequently.
Add mushrooms to skillet .
Saute until tender about 15 minutes. Stir frequently.
Add salt and pepper to mushroom onion mixture (to taste).
Remove from heat and set aside.
Mix egg and milk together with a whisk until well blended.
Paint the puffed pastry with the honey mustard leaving a 1/2 inch border.
Add the mushroom onion mixture on top of the mustard leaving about a 1/2 inch border.
Sprinkle the cheese on top of the mushroom onion mixture.
Paint the border of the puffed pastry dough with egg wash (Discard leftover egg wash).
Place tart in oven and bake for 15-20 minutes until pastry has puffed up and browned.
Enjoy!