Utah fry sauce 

Utah fry sauce (also "fry sauce") is a mixture of mayonnaise and ketchup in a 2:1 ratio generally meant for dipping french fries and onion rings, although it can be put on hamburgers. It is attributed to the Utah-based fast-food chain Arctic Circle ca. 1948. However, it also resembles a simplified version of pre-existing Thousand Island dressing. According to Wikipedia, similar sauces are widely known elsewhere, including "mayoketchup" in Puerto Rico, "Burger Sauce," "Pink Sauce" (also "Salsa Rosada" in S. American countries), even "Cockteilsauce."

Provo drive-through loudspeaker: "Would you like _eye _oss with that, Sir?"

Out-of-town customer: "What?"

Loudspeaker: "Utah fry sauce, Sir? Or maybe you'd prefer ketchup? ... Or both?"

Out-of-town customer: "That's fine, thanks."

Utah fry sauce by al-in-chgo April 28, 2014