Preheat the oven to 375°F.
Invert two 2-cup baking dishes or one 1-quart baking dish on a piece of parchment paper and trace around the dishes. Cut out the shapes for templates.
On a lightly floured work surface, roll out the dough to smooth out the creases. Place the parchment templates on top then cut around the templates with a knife. Using a small sharp knife or small heart-shaped cookie cutter, cut a small hole in the center of the dough for the vent. Place pastry on a parchment-lined baking sheet and brush with the egg. Bake until puffed and golden, 7-10 minutes and remove. Turn off the oven and place the baking dishes inside to keep warm.
Meanwhile, bring stock and the porcini mushrooms to a simmer in a small saucepan over medium-high. Simmer until the porcinis soften and flavor the stock, about 5 minutes.
In a large cast-iron or other heavy skillet, heat the oil, two turns of the pan, over medium-high. Add the pancetta and cook until browned, about 8 minutes. Melt in butter then add the fresh mushrooms, bay leaf and herb bundle. Brown mushrooms, about 8 minutes, then add the shallots and garlic, and season with salt and pepper. Cook, stirring often, until the shallots soften, just a couple of minutes. Sprinkle with 2 tablespoons flour and stir until well incorporated, just a minute more. Add the wine and cook until reduced by half, 4-5 minutes.
Using a slotted spoon, transfer the porcinis to a work surface; chop and add to the filling skillet. Add the mushroom stock, leaving behind any grit in the saucepan. Add the chicken and stir until heated through; add more stock if the filling is too thick.
Divide the chicken mixture between dishes, top with the pastry and serve.MORE
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