20061231 Jiffy Burger
No, that's not cheese and it's not mustard. It's peanut butter.
Here's the description: "Our great burger covered with peanut butter, thick cut bacon and jack cheese." As you can imagine, warm peanut butter gets very sloppy. My hands got covered, and it was spilling off onto my pickle and fries.
From Fanny Ann's Saloon in Old Sacramento.