I want to make a classic brown gravy to serve with my rib roast and mashed potatoes. I use the Serious Eats' method to cook the roast (reverse sear) and have found I don't get much in terms of drippings; there is enough fat left in the pan, but little else. What do you recommend I do to ensure a flavorful brown gravy? I was thinking about cutting a sliver of meat from the roast, cutting it into pieces, and spreading it on the bottom of the pan to get some beefy flavor. Suggestions? Thanks so much.