I was in a restaurant in Seattle a couple of weeks back. Their menu had a sidebar on it titled "the benefits of beef tallow". Bingo! I ordered some fries, in spite of it coming alongside a breakfast meal, and they were really good.

Best fries I ever had were at a flatmate's parents' place in Normandy. As you probably guessed, cooked in duck fat. Not sure how much of that is nostalgia and my memory playing tricks as that was back in the early 70s.