Pot pie - a closed chicken pie

Ingredients:

• 5 tablespoons cake flour, plus extra for dusting the cooking surface
• 1 sheet puff pastry, thawed according to package directions
• 4 cups lightly salted chicken broth
• 1 teaspoon black peppercorns
• 3 sprigs thyme, 1 tbsp finely chopped leaves
• 2 bay leaves
• 1 large onion, cut into 4 pieces
• 4 chicken breasts, boneless and skinless
• 3 tbsp (45 g) unsalted butter
• 1/2 cup frozen pearl onions (onion sets), thaw before cooking
• 2 medium carrots, diced
• 1 cup sliced ​​porcini mushrooms
• 1 cup frozen peas, thaw before cooking
• 1 cup of milk
• Table salt and freshly ground pepper
• 1 large egg, lightly beaten
• Equipment: You will also need 4 ovenproof bowls or small baking dishes, each holding 2 cups of water.

Preparation:

1. Prepare the cake layer.
   
   Line a baking sheet with parchment paper. On a lightly floured surface, roll the dough out with a rolling pin to a square approximately 30 cm in size. Transfer the dough to the prepared parchment paper, cover with plastic wrap, and refrigerate while you prepare the filling.
2. Prepare the chicken.
   
   Combine chicken broth, peppercorns, thyme sprigs, bay leaf, and quartered onion in a large saucepan over high heat. Bring to a boil and simmer for 30 minutes.
3. Add the chicken to the pan. Increase the heat and bring the mixture back to a boil, then simmer until the chicken is cooked through, about 10-15 minutes. Using tongs, transfer the chicken to a plate and let it cool. Strain the broth through a fine sieve. You'll need 2.5 cups of the broth for the filling; reserve the remaining broth for later. Once the chicken has cooled, cut it into small pieces.
4. Prepare the filling.
   
   Preheat oven to 375°F (190°C). Melt the butter in a saucepan over medium heat. Add the pearl onions and carrots, stirring occasionally, and cook until softened, about 5 minutes.
   
   Add the mushrooms and peas and simmer for another 5 minutes. Stir in 5 tablespoons of flour and cook, stirring, for another minute. Stirring constantly, pour in 2.5 cups of chicken broth and milk. Cook until thickened, about 5 minutes. Remove the pan from the heat. Add the chicken and finely chopped thyme leaves; season with salt and pepper.
5. Form a closed pie.
   
   Prepare 4 bowls or baking pans. Transfer the dough to a floured surface. Using a sharp knife, divide the dough into 4 pieces, each slightly larger than the top of the pan.
6. Place the molds on a baking sheet and fill them with the filling. Cover each mold with the dough, pressing it firmly around the edges. Brush the dough with a lightly beaten egg. Make a small slit in the center for air circulation. Bake until the dough has risen and is deep golden brown, about 35 minutes.