- Line a baking sheet with aluminum foil for easy clean-up.
- Lay out 2 sheets of defrosted premade puff pastry and place an indivdual pie dish (or round soup bowl) upside down on the pastry. With a sharp knife cut a circle around the bowl that is about 5 cm in diameter larger than the bowl. Place the dough rounds on the foil-lined baking sheet and refrigerate until ready to use.
- Preheat the oven to 220°C and set an oven rack to the center position.
- To make the filling: In a large sauté pan over medium heat, melt the butter. Add the yellow onion, garlic, celery, pearl onions, and carrots. Sauté, stirring occasionally, until the carrots are just cooked, 8 to 10 minutes. Add the flour and cook, stirring constantly, for about 2 minutes. Add the broth, cognac, salt, and white pepper. Bring to a boil, stirring with a wooden spoon and scraping the bottom and corners of the pan to incorporate the flour. Simmer until thickened, a few minutes. Off the heat, stir in the heavy cream, thyme, chicken, and peas. Taste and adjust seasoning, if necessary. (Note that the broth will taste a little boozy at this point. That’s okay – the cognac will cook off in the oven.)
- Ladle the filling into 4 individual pie dishes or oven safe soup bowls. The filling should come up no more than three-quarters of the way to the top of the bowls. Do not overfill. Use more bowls and cut more pastry rounds if there is enough left over mixture to make more pies.
- Beat the egg with 1 tablespoon of water.
- Remove the pastry rounds from the refrigerator. Brush the outside edges of each bowl with the egg wash.
- Place the cold dough rounds over the bowls, pressing firmly around the edges so that the dough adheres. Transfer the bowls to the foil-lined baking sheet. Brush the dough with the egg wash. Using a sharp knife, make a 1cm slit in the top of each pie. Place the bowls on the foil-lined baking sheet and bake for 20 to 25 minutes, or until the pastry is a rich golden brown. Let cool for about 10 minutes, then use a wide spatula to carefully transfer the hot bowls to serving plates. Sprinkle a few fresh thyme sprigs over top of the bowls and serve.
Click here to see the original recipe