Slice the ftira roll in half horizontally.
Drizzle both sides with a little olive oil.
Layer the tuna, tomato, onion, capers, and olives evenly on the bottom half.
Season with salt and pepper, and add herbs if using.
Press the top half of the bread down firmly to help the flavors merge.
Serve immediately, or wrap and let rest for 15–30 minutes for even better flavor.