Once the roux is smooth, gradually add milk and continue to cook, stirring constantly, until sauce thickens.
(If you have leftover gravy, you can skip this step and simply heat the gravy in a saucepan.)
Mix the meat and vegetables into the gravy and pour into an unbaked pie crust.
Place the top crust on, crimp the edges, and make several small slashes across the top to vent.
Bake at 425° for 25 minutes or until the crust is golden and the meat filling is bubbling.
Notes / Tips / Wine Advice:
This is a forgiving recipe. You can use nothing but meat if that’s all you have. Mix and match vegetables to suit your taste. Also, once you add the meat, try not to overstir—stirring too much will shred the meat.