Their adventures were documented in the PBS special Spain...on the Road Again, and within their cookbook, Spain...a Culinary Road Trip, which contains all the recipes they fell in love with while abroad.
The Iron Chef even whipped up mouthwatering paella with Oprah and Gwyneth.
"We're making paella, which is probably the most famous dish in all of Spain," Mario said. "In each different region, there are different kinds of paella. I like to think of it as kind of a canvas on which you can paint."
Get Mario's recipe for Paella and other Spanish dishes.