This my friends is the famous french sandwich called a Pan Bagnat. It is the perfect addition to any picnic or get together. I made a few this week for a french picnic themed event and it was the star of the show. A couple of tips for making this sandwich "ooh la la" is to buy the more expensive oil packed tuna in herbs and to press the sandwich (I used a cast iron skillet) for about an hour after making to really distribute the juices. It's a little messy....but totally worth it!