Although chuck roast is inexpensive and rich in flavor, the meat tends to be tough because the chuck is located in the well-developed, heavily exercised shoulder area of the beef. A baking bag seals in the moisture and helps to tenderize the meat by breaking down the tough fibers. A baking bag provides a number of additional benefits, including versatility, convenience and easy cleanup. Because no oil is needed, the meat is relatively low in fat.
Coat the inside of the baking bag with a small amount of all-purpose white flour. Season the chuck roast with salt and pepper, along with your choice of fresh or dried herbs herbs such as rosemary, sage or thyme.
Place the bag in a large roasting pan with a depth of 3 to 4 inches.
Place the meat in the bag. If desired, add vegetables such as minced garlic and 1-inch chunks of onions, carrots, potatoes, mushrooms, turnips or celery.
Add a small amount of water, beef broth or liquids such as tomato sauce, wine or beer. As a general rule, use about 1/4 to 1/2 cup of liquid for a large baking bag.
Close the bag securely with the heat-proof tie included in the package. Make four to six, 1/2-inch slits in the bag with a tip of a knife or fork, then tuck the ends of the bag into the pan so the bag doesn't hang over the sides.
Place the pan on a lower rack in an oven preheated to 325 degrees Fahrenheit. Allow at least 8 inches around the pan because the bag will expand as it cooks. Be sure the bag doesn't touch the upper oven rack, heating element or the sides of the oven.
Cook the beef until it's ready. With most roasts that would be until a meat thermometer inserted into the bag registered at least 145 F, but chuck roasts are a special case because of their naturally chewy texture. They're best when cooked further, to the point of being fork-tender. Cooking time is approximately 1 hour and 45 minutes for a 1 1/2-to-2 1/2-pound roast, or 2 to 3 hours for a 2 1/2-to-5 pound roast.
Remove the pan from the oven and allow the meat to stand for 5 minutes. Open the bag carefully by slitting the top with a knife or scissors.
Transfer the roast to a serving plate, then cut and serve.