Deep-Dish Chicken Pot Pie

This one's for Kathryn. Also - lower in fat than the regular version, especially because it only has one crust!

3 medium leeks or 1 large onion, chopped
1 cup sliced fresh mushrooms (optional)
1-2 chicken breasts, cut into chunks
2 Tablespoons butter
1/3 cup flour
1 teaspoon poultry seasoning
1/4 teaspoon salt
1/4 teaspoon black pepper
1 1/2 cups chicken broth
1 cup half-and-half, light cream, or milk
1 cup frozen mixed vegetables (carrots, peas, corn, beans, etc.)
1 beaten egg white
Pastry topper (below)

In a large saucepan cook leeks or onion, mushrooms (if using), and chicken pieces in hot butter over medium heat for 4-5 minutes or until cooked through and vegetables are tender. Stir in flour, poultry seasoning, salt, and pepper. Cook for another minute or two. Add broth and milk all at once. Cook and stir until thickened and bubbly. Stir in frozen vegetables (as much as you'd like). Pour into a 2-quart baking dish.

Prepare pastry topper and place over chicken mixture in dish. Turn edges under; flute to edges of dish. Brush with beaten egg white. With a sharp knife, cut slits in the top for steam to vent.

Bake, uncovered, at 400 degrees for 30-35 minutes or until crust is golden brown. Let stand 5-10 minutes before serving.

Pastry Topper:
1 1/4 cups flour
1/4 teaspoon salt
1/3 cup shortening
4-5 Tablespoons water

Stir together flour and salt. Using a pastry blender, cut in shortening until dough pieces are pea-size. Sprinkle cold water over the mixture, one tablespoon at a time; gently toss with a fork. Push moistened dough to side. Continue sprinkling water and tossing until all dough is moistened. Form into a ball and turn out onto a sheet of plastic wrap. Cover with another sheet of plastic wrap and roll dough out until it's the size of your baking dish. Use the plastic wrap to help transfer the pastry to top the dish. (Also makes clean-up easier!)