The spleen is an organ in the upper left abdomen, which filters blood, disposes of worn-out red blood cells, and provides a 'reserve supply' of blood. It contains both red tissue, and white lymphatic tissue. The major (encapsulated) lymphatic organs are the lymph nodes, thymus and spleen.
Place the brined corned beef in a large pot or Dutch oven along with the liquid and spices that accompanied it in the package. Pour in enough water to cover the beef, then bring the water to a boil on the stovetop. Reduce the heat to a simmer, and cover the pot. A three-pound corned beef could take three hours or more to become perfectly tender. Check the meat occasionally, adding more water if necessary. The beef is ready when it pulls apart easily.
The USDA recommends cooking to medium, but this lean, tougher cut turns out better at medium-rare. A boneless beef cut like a top round roast typically takes 30 to 35 minutes per pound to reach the USDA-recommended temperature of 145 degrees Fahrenheit when roasted at 350 F, a total of 120 to 140 minutes.