Method
1
Rehydrate and pre-cook porcini
Pick over 15 g dried white porcini and soak in 600 ml lukewarm drinking water for about 15–30 minutes until soft through the thickest pieces. Keep room-temperature soaking within 2 hours and refrigerate longer waits. Discard the water, rinse each piece free of grit and place in about 1.2 litres fresh water. Bring to the boil and simmer for 40–60 minutes until fully cooked without a dry, hard centre. Drain, discard this cooking liquid and roughly chop large pieces. This follows the product cooking instructions; briefly frying the filling or baking the pie does not replace pre-cooking.

2
Cook a thick chicken and mushroom filling
Keep chicken chilled until needed and do not rinse it. Melt butter in a heavy pan. Soften leeks over a medium-low heat for about 8 minutes, add garlic and thyme for 1 minute, then cook the fresh mushrooms for about 5 minutes until excess moisture has evaporated. Add chicken and cook for 3–4 minutes. Stir in flour and cook for 1–2 minutes. Gradually stir in stock, then cream, cooked porcini and pepper. Simmer for about 10–15 minutes until the sauce coats a spoon. Check the largest chicken pieces with a clean probe: the centre must reach 75°C for 30 seconds; cook longer if necessary. Taste before adding salt.
3
Cool the filling and prepare the lid
Transfer the cooked filling to a shallow 22–24 cm pie dish holding about 1.5–2 litres, leaving about 2 cm clear below the rim. Cool promptly for roughly 30–60 minutes until no longer steaming and cool to the touch, then cover and bake immediately. Use or refrigerate cooked filling within 2 hours of cooking; for advance preparation, cool quickly in a shallow container and refrigerate. Keep the pastry chilled until assembly.
4
Cover, glaze and vent
Preheat the oven to 200°C conventional / 180°C fan. Lightly brush the dish rim with beaten egg, add the cold pastry lid, press the edge to seal and trim any excess. Use trimmings for a simple decoration if you wish. Glaze lightly with egg and cut 2–3 vents in the centre. Set the dish on a baking tray to catch any escaping sauce.

5
Bake until golden and hot in the centre
Bake for about 35–45 minutes until the pastry is well risen, golden and cooked beneath, and the filling bubbles. Insert a clean probe through a vent into the central filling: it must reach 75°C for 30 seconds. Chilled filling may take longer. Loosely cover with foil if the top colours too quickly. Rest for 5–10 minutes before serving, taking care with the hot dish and steam.
Cooking tips
- Difficulty: Intermediate.
- This pie has a pastry lid and no pastry base. A thick sauce and cooled filling help prevent a soggy underside.
- The porcini pack weighs 100 g; this recipe uses only 15 g dry. The 200 g fresh mushrooms are a separately bought supporting ingredient.
- If the filling has been cooked, chilled and then baked, that baking is its one reheating. Bake only what you need and do not reheat those leftovers again.
Allergens
Contains milk, egg and wheat. Stock and pastry may contain celery, soya or other allergens; check labels. The Xianyitang dried-ingredient packs state that they are packed in a facility also handling peanuts, tree nuts, sesame and soya. Check the actual labels of every brand used.
Storage and reheating
Keep raw meat and rehydrated fungi refrigerated at 5°C or below and follow meat-pack use-by instructions. Keep raw and cooked utensils separate. Cool cooked leftovers promptly in shallow containers, refrigerate within 2 hours, and eat within 48 hours or freeze. Reheat only once until hot throughout. If baking previously chilled cooked filling, do not reheat the baked leftovers again.