INSTRUCTIONS

1. Arrange rack in center of oven. Preheat to 400°F. Lightly butter a 9 x 9-inch baking dish, then set on a large, rimmed baking sheet. Set aside.
2. Melt butter in a large pot over medium heat. Add carrots, fennel, shallots, garlic, sage, and thyme. Season with ½ tsp salt and black pepper. Cook, stirring occasionally, until shallots are soft, about 8 to 10 minutes. Stir in flour to coat, then cook, stirring constantly, for 2 minutes. Slowly stir in chicken broth, then cream, mustard, and remaining ½ tsp salt. Continue cooking, stirring often, until mixture is thick and saucy, approximately 6 to 8 minutes. Remove from heat and stir in turkey to combine.
3. To assemble, combine egg with water in a small bowl. Set aside. Transfer turkey-mixture to prepared baking dish, spreading to evenly fill. Drape puff pastry sheet overtop, gently pressing along the edges of the dish to seal. Brush pastry with egg wash, then using a sharp knife, cut a few slits in the pastry to vent.
4. Bake in the center of oven until pastry is golden and filling is bubbling along the edges, about 35 to 40 minutes. Let it stand for 10 minutes before serving.