Step 1 Preheat oven to 200°C. In a frying pan, heat oil. Add onion and garlic and cook until soft. Add mushrooms and cook, stirring frequently, until slightly softened.

Step 2 Stir in brandy and herbs, then add breadcrumbs, cashews and soy sauce. Remove from heat. Mix well, then allow to cool. When cooled, add 3/4 of beaten egg. Use the rest to glaze pastry.

Step 3 Spray a baking tray with oil spray. Create 2 long rectangles of pastry, each 35cm x 15cm, by cutting pastry and joining as necessary. With a rolling pin, roll the joins gently to secure. Place 1 long rectangle on the tray.

Step 4 Brush pastry edges with water, then leaving a 1cm border to avoid spilling, pile on mushroom filling. Top filling with remaining pastry rectangle. Press firmly around edges, then use a metal spatula or the spine of a knife to crimp. Neaten edges.

Step 5 Cut incisions at 1cm intervals in pastry lid. Brush with remaining beaten egg. Bake for 25 minutes, or until pastry is a rich golden colour.