Cook sausage in cast iron pan until well done.
Remove from pan and pour off all but ¼ cup of fat.
Turn off heat to prevent scorching and add the flour to the drippings.
Cook and stir over medium heat 5 to 10 minutes or until mixture starts to turn golden. (This burns away the raw flour flavor which must be done before liquid is introduced)
Slowly add milk, stirring constantly.
Cook gravy until it boils and thickens.
Add sausage, salt, and pepper when gravy is nearing the desired consistency.
