
Preheat the oven to 350 ℉. Line a baking sheet with tin foil.
Preheat the oven to 350 degrees.
Dry the chicken with paper towels and then place the breasts on the baking sheet. Brush with the olive oil and season with salt and pepper. Roast in the oven for 35 minutes. Remove from the oven and cool. Discard the bones and skin and cut off the meat. You need at least 5 cups of chicken. Set aside.
Raise the oven tempt to 400℉.
In a heavy stockpot, melt the butter over medium heat. Stir in the leeks and carrots and saute for 8-10 minutes, until they soften. Add the garlic, mushrooms, and tarragon. Saute for 8 minutes. Then sprinkle the flour on top and stir for 30 seconds.
Stir in the chicken broth and sherry. Bring the pot to a boil and then lower to a simmer. Simmer for 5 minutes, until the sauce begins to thicken. Add the cream, 2 teaspoons of salt, 1 teaspoon of pepper, and simmer for another 5 minutes. Stir in the frozen peas and chicken. Taste and adjust the seasonings.
Divide the chicken and sauce into 6 2-cup ramekins.
On a lightly floured counter, roll out three pastry sheets to an 11" square. Cut out two circles from each sheet of pastry that are at least 1/2" larger than the rim of the ramekin. Brush the edges of the ramekins with the egg wash. Place the pastry circles over the ramekins, pressing the dough to the edges of the ramekins. Then brush the pastry with the egg wash and sprinkle fleur de sea on top. Add pepper if preferred. Cut three slits on the top of each pastry. Refrigerate the pot pies for 30 minutes. Then bake for 30-40 minutes, until the crust is puffy and golden brown and the filling is bubbly. Serve immediately.