Braised Chicken Pie with Caramelized Onions, Mushrooms and Chestnuts

Cut X in flat side of each chestnut. In saucepan of boiling water, cook chestnuts, 4 at a time, for about 2 minutes or until skins can be easily peeled off. Set aside.

In large bowl, combine flour, salt and pepper. In batches, toss chicken in flour mixture, reserving any unused mixture. In large Dutch oven, heat 2 tbsp (25 mL) of the oil over medium-high heat; brown chicken, in batches and adding up to 2 tbsp (25 mL) more oil as needed. Remove from pan and set aside.

Add carrots, chopped onions, garlic and thyme to pan; cook over medium-low heat, stirring often, for 5 minutes. Sprinkle with any remaining flour mixture; stir well. Return chicken to pan. Add stock and bring to boil, stirring. Reduce heat to low; cover and simmer for 15 minutes. Add chestnuts; cook for about 15 minutes or until chicken is no longer pink inside.

Meanwhile, in large skillet, heat remaining oil over medium heat; cook mushrooms and pearl onions, stirring often, for 25 minutes or until onions are tender and no liquid remains. Add to chicken mixture; cook for 5 minutes. (Make-ahead: Refrigerate in shallow airtight container, uncovered, to cool quickly. Cover and store for up to 2 days or freeze for up to 2 weeks; thaw before proceeding.)

Stir parsley into chicken mixture. Transfer to deep oval 12-inch (30 cm) gratin dish or 12-cup (3 L) glass baking dish.

Topping: On floured work surface, roll out half of the puff pastry to same size as dish; with cookie cutter, cut small star out of centre for vent hole. Place over filling, without sealing to edge. Roll out remaining pastry; cut out different-size stars. Brush egg yolk over pastry top; arrange cutouts on pastry and brush again with egg yolk.

Place dish on rimmed baking sheet; bake in 400°F (200°C) oven for 45 to 60 minutes or until bubbling and pastry is puffed and golden. Let stand for 10 minutes.