a sandwich containing a steak. Use of the term "steakburger" dates to the 1920s in the United States. In the U.S. in 1934, A.H. "Gus" Belt, the founder of Steak 'n Shake, devised a higher-quality hamburger and offered it as a "steakburger" to customers at the company's first location in Normal, Illinois. This burger used a combination of ground meat from the strip portion of T-bone steak and sirloin steak in its preparation. Steakburgers are a primary menu item at Steak 'n Shake restaurants, and the company's registered trademarks included "original steakburger" and "famous for steakburgers." Steak 'n Shake's "Prime Steakburgers" are now made of choice grade brisket and chuck. Beef is typical, although other meats such as lamb and pork may also be used. The meat is ground or chopped. In Australia, a steak burger is a steak sandwich that contains a whole steak, not ground meat. Steak burgers may be cooked to various degrees of doneness. Steakburgers may be served with standard hamburger toppings such as lettuce, onion, and tomato. Some may have various additional toppings such as cheese, bacon, fried egg, mushrooms, additional meats, and others. Various fast food outlets and restaurants such as Burger King, Carl's Jr., Hardee's, IHOP, Steak 'n Shake, Mr. Steak, and Freddy's market steak burgers. Some restaurants offer high-end burgers prepared from aged beef. Additionally, many restaurants have used the term "steakburger" at various times. Some baseball parks concessions in the United States call their hamburgers steak burgers, such as Johnny Rosenblatt Stadium in Omaha, Nebraska. Burger King introduced the Sirloin Steak sandwich in 1979 as part of a menu expansion that, in turn, was part of a corporate restructuring effort for the company. It was a single oblong patty made of chopped steak served on a sub-style sesame seed roll. Additional steak burgers that Burger King has offered are the Angus Bacon Cheddar Ranch Steak Burger, the Angus Bacon & Cheese Steak Burger, and a limited edition Stuffed Steakhouse Burger. In 2004, Steak 'n Shake sued Burger King over the latter's use of the term Steak Burger in conjunction with one of its menu items, claiming that such use infringed on trademark rights. (According to the St. Louis Post-Dispatch, Burger King's attorneys "grilled" Steak 'n Shake's CEO in court about the precise content of Steak 'n Shake's steakburger offering.) The case was settled out of court. United States and Canada The