Preheat the oven to 450°F. Roll out the sheet of pastry dough (including the parchment wrapper) onto a work surface (for 4 servings, lay out both sheets, overlapping slightly, so that it will cover a large pan). Place a medium cast-iron or oven-safe pan (or large for 4 servings) upside down on top of the puff pastry. Using a small knife, cut the dough around the diameter of the pan. Discard any excess dough. Keeping it on the parchment, place the cut pastry dough in the refrigerator to keep cool.

Wash and dry the fresh produce. Halve, peel, and small dice the onion(s). Quarter the mushrooms. Peel and small dice the carrots. Small dice the celery. Pick the thyme leaves off the stems.

In the same pan, heat a drizzle of olive oil on medium-high until hot. Add the diced onion(s) and quartered mushrooms. Cook, stirring occasionally, 3 to 4 minutes, or until slightly softened. Add the diced carrots and diced celery. Cook, stirring occasionally, 3 to 4 minutes, or until softened. Season with salt, pepper, and the spice blend. Add the thyme leaves and pulled chicken (tearing the pieces apart before adding). Cook, stirring frequently, 1 to 2 minutes, or until the chicken is heated through. Carefully add the cream (shaking the packet before opening), butter, béchamel, and 1/4 cup of water (or 1/2 cup for 4 servings). Cook, stirring freqeuntly, 30 seconds to 1 minute, or until thoroughly combined and the butter is melted. Turn off the heat.

Carefully top the pan of cooked filling with the cut pastry dough (discarding the parchment); gently press down along the edges of the dough to tightly cover the filling. Cut a 2-inch slit on the top of the pastry dough. Bake 12 to 16 minutes, or until the pastry is golden brown and cooked through. Remove from oven and let stand at least 3 minutes before serving. Enjoy!