Close, but not quite
As mentioned,cheese, onions and garlic are not a usual part of the recipe, tho there may be some regional variations. Tho I may give that a try since I like to play around with recipes.
But I think another problem with the gravy is you made it with the sausage still in. Best to take the sausage out, then make the roux and add the liquid. Yours was probably tasty, but definitely too thick.