I use a pound of Jimmy Dean regular or 'hot' sausage.
Brown it - break it up into tiny bits
The gravy part -
Add 2 T butter to the browned sausage - let it melt
4 T flour
Stir it up
Add 2 cups milk
Cook - stir until thickened
Basically - just a white sauce with sausage in it - get some of the fat from the sausage
I usually don't add anything more to it - maybe some black pepper -