Get a large skillet fired up over medium and brown the sausage for a good 10 minutes. Really try breaking down the sausage bits as best ya can. When she's browned up in small sausage-y bits, we'll be ready to go get the rest added in.
Throw the butter in there and melt her down. Sprinkle in the flour, garlic, and pepper stir it up until all that goodness is soaked up. I had some stubborn sticking to the pan, but work it all in.. you don't want to lose the flavor. Keep a steady stir for few minutes before adding the milk.
We're going to trickle in that milk. I did about a 1/2 cup at a time, all the while stirring it up. She'll take a good 5 minutes to thicken up, but this is where the result pops, so don't rush it. Hit it with a little salt, if you wish and if it's a bit thick, sprinkle in a little more milk until it's to your desired consistency.
Skillet has that hot gravy, your biscuits are warm - ladle that gravy on top and eat it up!