Preheat a 4-quart saucepan over medium high heat (put a few drops of water in the pan - when they evaporate, you know the pan is ready). Crumble the sausage into the pan and let it brown for a minute or two, then turn down to medium heat. Continue cooking, breaking up the sausage into smaller pieces, until no pink remains. Stir in the onions and cook until they are transparent.

Remove sausage with a slotted spatula or spoon, leaving the drippings in the pan. If less than 3 tbsp of drippings remain, add enough butter (or bacon grease) to equal about 3 tbsp of drippings. Add the cooked sausage back to the pan on medium heat, and sprinkle the flour over the sausage. Stir in the flour and cook for about 6-8 minutes, until the mixture starts bubbling and turns slightly golden brown.

Stir in poultry seasoning, salt and pepper. Cook for 1 minute to deepen the flavors. Slowly add the milk and cook over medium heat, stirring occasionally, until thickened (about 15 minutes). Be patient, it will thicken!