Preheat oven to 250 degrees.
In a bowl, combine flour and salt.
Cut in shortening until crumbly.
Add lemon juice, egg, and cold water.
Mix until a dough forms.
Roll dough to fit a greased pie dish and set aside.
In a large bowl, combine chicken, cream of chicken soup, chicken broth, and mixed vegetables.
Pour filling into the prepared baking dish.
Place crust over the filling.
Cut vents in the top crust.
Bake for 2½ hours until crust is golden and filling is bubbly.