Things You'll Need
13 inch by 9 inch disposable aluminum roasting pan
Instant-read meat thermometer
Sirloin roast is a cut of beef taken from the cow's hind portion. It is one of the thickest, most affordable cuts of beef, but it contains a large amount of muscle. Muscular cuts of meat have connective tissues that make the meat tough and chewy. A tender sirloin roast requires a long cooking time so the connective tissues can dissolve. Grilling can add more flavor to this lean cut of meat, but it is key that you don't use a high temperature or else the meat's juices will dry up.
Coat each side of the sirloin roast evenly with salt and pepper. Set your grill to a medium heat.
Place the sirloin roast directly onto the grill. Heat for about two minutes per each surface side--approximately 10 minutes total--or until the entire outside of the roast is lightly browned. Hold the roast in place with tongs while it heats if it won't stay in place due to its irregular shape.
Place the browned sirloin roast into the center of a 13 inch by 9 inch disposable aluminum roasting pan. Wrap the pan lightly with aluminum foil and add the entire pan onto the center of the grill.
Heat the covered sirloin roast on the grill for about three hours, then check it. Use a fork to slice through the meat to determine if it's done and add it back to the grill for another 30 minutes if not. Remove the pan from the grill once the meat easily shreds with a fork.
Stick an instant-read meat thermometer directly into the thickest part of the meat. Make sure the thermometer displays between 145 and 160 degrees Fahrenheit or else add it back onto the grill for another five minutes or until it reaches the correct temperature. Slice the finished roast into pieces as thin as possible before serving.
Add cut up carrots or potatoes to the roasting pan along with the sirloin roast for a one-dish meal.
Place the sirloin roast into a large resealable plastic bag along with enough red wine or beef broth to cover it and store in the refrigerator for a minimum of two hours for an even more flavorful roast.
Do not eat beef with an internal temperature of less than 145 degrees Fahrenheit because it may contain harmful bacteria, according to the United States Department of Agriculture (USDA).