Pan Bagnat with Fennel

Preparation

1. Fennel and olives:

   Step 1

   Toss fennel, olives, oil, vinegar, capers, and red pepper flakes in an airtight container or resealable plastic bag; season with salt and pepper.

2. Do Ahead

   Step 2

   Fennel-olive mixture can be made 2 days ahead. Cover and chill.

3. Assembly:

   Step 3

   Toss fennel-olive mixture with cucumber and tuna in a medium bowl; season with salt and pepper. Let sit, tossing occasionally, 10 minutes.

   Step 4

   Scoop out inside from top half of bread; discard (or save for a snack!). Layer bottom half of bread with tuna mixture, then top with eggs and arugula. Close up sandwich.

   Step 5

   Place a large heavy skillet or pot on top of sandwich to weigh down and let sit at room temperature, turning once, until evenly pressed, about 2 hours (if making sandwich at home, or storing in a cooler while you hike, wrap it up tightly in plastic wrap before you press it).

   Step 6

   Slice pan bagnat into wedges just before serving.