In a medium pan, add the butter and the onions and let them get golden and caramelized. Stir to keep them evenly coated in the butter. Mix the ground beef with the soup packet and form burger patties.
For the uninitiated, an Oklahoma-style burger, which dates to the 1920s, features a bundle of thinly sliced onions frizzled on a griddle (not caramelized, but instead fried translucent with ...