This was one that was meant to help me squelch the mac-and-cheese cravings I occasionally get when my two young boys eat the full carb stuff. It's a relatively simple adaptation of a basic keto gravy.
The mixture will thicken very considerably. Add the cheddar cheese an ounce at a time, whisking until it melts and incorporates. You may have to stop short of the full 4 ounces if it gets too thick.