Pan Bagnato

Directions

1. 1
   Slice baguette in half crosswise, then slice each half lengthwise in two, making bottom halves larger.
2. 2
   Pull out and discard the insides so you have hollow bread shells.
3. 3
   In a measuring cup or small bowl, whisk together vinegar and mustard.
4. 4
   Whisk in olive oil until emulsified, then season with pepper.
5. 5
   Brush some of the vinaigrette over the insides of the bread shells.
6. 6
   In a bowl, stir together the tuna, capers, onion, and olives; stir in the remaining vinaigrette until well combined.
7. 7
   Mound tuna evenly in the bread shell bottoms.
8. 8
   Arrange tomatoes and basil leaves over tuna, then put tops of bread on.
9. 9
   Squish down to compress ingredients: you want the bread to get soaked with the flavors.
10. 10
    Wrap tightly in plastic wrap and parchment to transport.
11. 11
    If made ahead, refrigerate up to 4 hours, wrapped.