I take tenderloins and cook them with salt, pepper, and butter if I need the fat. Then once they are cooked, I remove the loins and add strong coffee and add it to the pan and simmer until it's as thick and concentrated as I want it. It's more of an aus jus than a thickened gravy. My dad did...
When I have it on biscuits, I cook it with lower salt so I can use more (I don't use flour in mine though) gravy...a little biscuit with my gravy 😁. Of course now I eat low carb so that's OK. I can have all the gravy I want 😋
Sorry, I was so hungry I took a bite out of it...keto bread, egg and ham cooked in butter, and red eye gravy...I'm in heaven no matter how gross it looks!
Or cook pork tenderloin in a fry pan til done, then add the strong coffee to the drippings and salt to taste and cook to preferred thickness. Serve over fresh buttered biscuits with chopped tomatoes. Yum yum.