This should be calledbagnat instead of pan bagnat (because it was a bit of a pain to make!).The word "pan bagnat" means "wet bread" in French and this sandwich is just that!Like a panzanella salad (bread salad) from Italy, where you moisten the bread with oil and vinegar to soften.This sandwich originated in Nice, France and is basically a Nicoise Salad in a loaf (minus the green beans). Next time I will stick with my Salade Nicoise, much easier to prepare.This was a chore to make, but worth the effort. There are a lot of ingredients involved and then you layer them in a hollowed out loaf of bread and weigh it down overnight with weights. You following me?I saw a great looking photo (never browse for recipes on line when you are hungry) on tastespotting I love the combination of ingredients and the photo was so pretty, so I decided to make one.(makes enough for 6 for lunch):1 baguette1 tablespoon red wine vinegar1 tablespoon lemon juice1/4 teaspoon sea salt1/8 teaspoon freshly ground black pepper3 tablespoons extra virgin olive oil1 cup black olives4 tablespoons capers1 clove garlic, minced2 cans Italian tuna in olive oil, drained and broken apart2 small boiling potatoes, boiled, cooled and sliced thinly2 hard-boiled eggs, peeled and sliced thinly2 small vine-ripened tomatoes, sliced thinly1/4 cup thinly sliced red onion1 cup arugula1. Halve the baguette lengthwise and scoop out a little of the interior of both sides with your fingers.2. In a small bowl, whisk the vinegar, lemon juice, salt and pepper until combined. Whisk in the olive oil until emulsified and set aside.3. Coarsely chop the olives and capers, then combine in a small bowl with the minced garlic and set aside.4. Fill the bottom part of the baguette with the olive mixture, spreading it evenly across the hollowed-out baguette. Layer the tuna over the olives, then, in even layers, add the potatoes, eggs and tomatoes. Drizzle the vinaigrette over the sandwich, then add the onions and the arugula, pressing down on the contents as you go. Top with the other baguette half and wrap the sandwich tightly with plastic. Refrigerate overnight, weighted with a cutting board or a plate topped with some cans or bottles.5. The next day, take the sandwich out of the refrigerator in the morning and cut into sixths. Wrap individually and pack for lunch: the sandwiches are best when they've been sitting at room temperature for a couple of hours.6. Eat and enjoy!