Chicken Wellington

Puff pastry, thawed	1 sheet
Chicken breast, boneless, skinless	4 small
Butter	2 tablespoons
Oil	2 tablespoons
Salt
Pepper, freshly ground
Onion, finely chopped	1 large
Garlic, minced	1 tablespoon
Mushrooms, Shitake, sliced	1/4 pound
Parsley, finely chopped	2 tablespoons
Cream cheese, softened	4 ounces
Mustard, Dijon	2 tablespoons
Egg, slightly beaten	1

1. Season the chicken with salt and pepper. 
2. Heat the butter and oil in a large skillet over medium-high heat. 
3. Brown the chicken on all sides until almost cooked through; transfer to a plate. 
4. Add the onions, garlic, and mushrooms; sauté until the mushrooms release their moisture and the onions are tender. 
5. Stir in the parsley. 
6. On a floured surface, roll out the pasty sheet to a 14-inch square; cut into four even 7-inch squares. 
7. Place a breast over each pastry square. 
8. Preheat the oven to 375°F. 
9. In a small bowl, combine the cream cheese and mustard, and then spread over each breast. 
10. Top each breast with about 3 to 4 tablespoons of the mushroom-onion mixture. 
11. Brush the edges of the pastry square with water, and wrap the pastry around the chicken, pressing the edges to seal tightly. 
12. Place seam-side down on a greased baking sheet, and brush the tops with egg wash. 
13. Bake for 25 minutes, or until puffed and golden brown.