The results were worth the minimal knife work: The trimmings gave up loads more fat and fond for the potatoes to soak up. (Starting the meat and trimmings in a cold pan maximized the amount of fat that was rendered, because the fat had time to melt thoroughly before the meat’s exterior browned too much.) I even doubled their efficacy by simmering the browned scraps with the broth before using it to braise the potatoes, which amped up the broth’s beefiness and the flavor of the spuds. Further doctoring the broth with garlic and herbs rounded it out; adding gelatin gave the reduced jus unctuous body.
Cooking the meat and potatoes together wasn’t tricky once I had extracted all that flavor and fat from the trimmings. But it did require a strategic setup. After searing the meat and scraps, I laid the potatoes cut side down in the pan, keeping them in a single layer to ensure even cooking, and covered them with aluminum foil that I’d poked holes in. That created a “rack” on which I placed the roast; it also allowed juices to drip through to the potatoes and trapped steam that helped the potatoes cook through. When the roast hit 115 degrees, I set it aside to rest; gingerly flipped the potatoes; added my beef-enhanced, strained broth (it simmered while the roast cooked); and finished the potatoes in a 500-degree oven.
It was a success: juicy, tender meat and creamy potatoes that tasted truly beefy.