That sizzling sound you heard this morning wasn't your usual rasher of breakfast bacon. The big thing cooking on Monday, August 5, was the world's first burger made from "cultured beef," grown in a lab from bovine stem cells. A burger isn't always 100 percent beef, of course, and such was the case with this historic patty. Today's serving also included salt, egg powder, and breadcrumbs, along with red beet juice and saffron to bring out its natural colors. The burger was cooked at an event in London.