A cast-iron roaster is ideal for cooking roasts because the thick, heavy pan evenly distributes and holds the heat. Plus, no additional liquid is required because the roast's own juices provide plenty of moisture. Searing the meat quickly in hot oil before roasting creates a savory, crusty outer covering. Cooked in cast-iron, even a budget-friendly roast such chuck, bottom round, rump, blade or shoulder roast is turned into a succulent, mouthwatering feast.
Remove the roast from the refrigerator, and allow it to warm to room temperature for 30 to 40 minutes.
Place a small amount of flour in a shallow plate or pie pan, then season the flour with salt and freshly ground black pepper. Lay the roast in the seasoned flour, turning until all sides of the meat are lightly coated.
Cover the bottom of a cast-iron roaster with vegetable oil or bacon fat. Heat the oil until it is shimmering, but not smoking.
Place the roast in the hot oil and cook it, turning frequently, until the meat is brown on all sides.
Turn the roast fat side up, and transfer it to an oven preheated to 325 degrees Fahrenheit.
Cover the pan and cook the meat, turning halfway through the cooking time, until a meat thermometer registers 145 F for a medium rare roast, or 160 F for a medium roast. As a general rule, allow approximately 30 to 35 minutes per pound for a 2 1/2- to 4-pound rump or round roast.
Transfer the roast to a cutting board and let it rest for 15 to 20 minutes. Cover the meat loosely with aluminum foil to keep it warm during the resting time.
Slice the roast. Transfer the sliced meat to a plate, and serve.