There are a few places here in Central Oklahoma (Johnnie's, Irma's) that serve what they call a 'Theta Burger', that is, a burger with hickory sauce, mayo, and pickles with shredded cheddar cheese. Are these an Okie invention? Anyone else ever had one? Even Sonic used to have one similar to this, but it's not on the menu anymore as they have gone more mainstream. They are pretty tasty, but I think the onion-burger is still king around here.