Though she was quick to say that there is no "best," Rachael did give away this much:
"Then you have a classic like Josh Capon [of Lure Fishbar], who is a four-time winner in New York. He always makes a classic burger. Bacon jam is like his secret ingredient, but basically it's like a straight-up soft bun. It's friendly and looks like a hamburger.
"Mike Symon has won three or four times here. He always does something with double meats, like tonight's Fat Doug burger with pastrami. Double meats are very popular. I don't think there's any one science to a burger."