Step 1

Preheat oven to 400 degrees. Unfold puff pastry onto a lightly floured surface, sprinkle top with a little flour then spread evenly over top.

Step 2

Cut puff pastry into 1-inch squares. Transfer to a 18 by 13-inch baking sheet lined with parchment paper.

Step 3

In a mixing bowl whisk together egg with the 1 Tbsp water until well blended. Light brush some of the egg mixture over top of puff pastry then spread pieces out even.

Step 4

Bake in preheated oven until nicely puffed and richly golden brown, about 11 to 15 minutes.

Step 5

While puff pastry is baking prepare filling. In a 12-inch skillet heat olive oil over medium-high heat.

Step 6

Add onions, celery, carrots, mushrooms and saute tossing only occasionally (about every 2 to 3 minutes so mushrooms and veggies brown a little), cooking until veggies soften, about 10 to 12 minutes.

Step 7

Add butter and garlic and saute 1 minutes. Sprinkle in flour, then cook tossing constantly 1 minute.

Step 8

Reduce heat to medium, while whisking slowly pour in chicken broth then milk. Add thyme and season with salt and pepper to taste. Let cook until thickened, while stirring.

Step 9

Reduce heat low stir in chicken. Let heat for a few minutes, stirring occasionally. Stir in peas, parmesan and parsley and warm through.

Step 10

Thin mixture with more chicken broth as desired (or milk). Serve warm in bowls and top with puff pastry pieces garnished with a little more parsley.