1. Preheat oven to 400°. Melt butter over medium heat. Sauté leeks 7 minutes. Sprinkle flour over leeks. Cook, stirring constantly, for 3 minutes. Whisk in chicken broth and next 3 ingredients; bring to a boil. Remove from heat. Add peas, corn blend, parsley, 2 teaspoons dill, and chicken. Mix well. Pour into a greased 9-inch deep pie dish.
2. Whisk together egg yolk and 1 tablespoon water, and brush underside of crust edge with egg wash. Place crust, brushed side down, over pie; crimp or use back of fork to seal rim of crust around dish. Cut 4 to 5 vents in the pastry. Brush top with egg wash, and sprinkle with remaining 1 teaspoon dill. Bake at 400° for 30 to 35 minutes or until pastry is golden brown and mixture is bubbling.
*For testing purposes, we used Birdseye baby corn mix with corn, carrots, and broccoli.
Note that packaged roasted, diced chicken, although convenient, tends to be salty, so be sure to taste before seasoning. To keep sauce from bubbling over in the oven, place on a baking sheet or seal edges of dough by pressing with back of a fork around the rim of pie dish.