1 large or 2 medium leeks, white and light green parts only, halved lengthwise and sliced into half-moons
8ounces mushrooms, sliced
3 cloves garlic, minced
1/2 teaspoon dried thyme
1/4cup all-purpose flour
1/2cup dry white wine*
1cup plus 1 tablespoon half-and-half
1cup frozen peas
3cups shredded cooked chicken (rotisserie is fine!)
1 sheet puff pastry, slightly thawed
1 large egg, beaten
Kosher salt and black pepper
Instructions
Make the mushroom stock: Place the dried porcini mushrooms in a small bowl and pour over the hot water. Set aside to steep for at least 15 minutes while you chop the leeks, mushrooms, chicken and garlic.
Once the mushrooms are done steeping, scoop them out of the mushroom stock and give them a little squeeze to extract as much liquid as your can. They should be rehydrated and soft. Place them on your cutting board, chop them into very small pieces and set them aside.
Preheat oven to 425°F.
Build the flavor base: Melt the butter in a large, oven-safe skillet over medium heat. Add the leeks and mushrooms and sauté for 7–10 minutes, or until all the liquid has released from the mushrooms and the leeks are soft and translucent.
Add the garlic and thyme and sauté for an additional 30 seconds, or until fragrant.
Make the roux: Sprinkle over the flour and stir through, cooking for another minute or so, or until no dry patches of flour remain. Add the white wine and cook until reduced, about 2 minutes. Gradually stir in the mushroom stock and 1 cup half-and-half, then cook, stirring occasionally, for 2–3 minutes, or until thickened.
Finish the filling: Stir in the frozen peas, cooked chicken, and chopped rehydrated porcini mushrooms. Cook for an additional minute just to warm everything through. Adjust seasonings to taste and spread the filling into an even layer.
Top with pastry: Gently lay the puff pastry over the top of the skillet, lightly folding over the corners to fit it into the pan. Use a sharp knife to cut a few small slits in the center of the pastry. Beat together the egg with the remaining tablespoon of half-and-half, then use a pastry brush to brush a light layer of egg wash all over the pastry.
Bake: Bake until puff pastry is golden brown and filling is starting to bubble, 20–25 minutes. Reduce oven temperature to 375°F, cover the pan with foil and bake for an additional 10 minutes, until puff pastry is baked through all the way and filling is bubbly and thick.
Let cool for a few minutes before scooping and serving.
Notes
You can find dried mushrooms near the fresh mushrooms in most major grocery stores. If you can’t find them, you can substitute the mushroom stock with an equal amount of chicken stock or vegetable stock.
If you can’t use wine, you can substitute it with an equal amount of chicken stock, or just leave it out.