Start by draining the tuna from the can and placing it in a bowl.
Add extra virgin olive oil, salt, black pepper, and lemon juice to the tuna. Mix everything together until well combined.
Slice the French bread and warm it up. Spread hummus on one side and harissa or Sriracha on the other.
Layer the tuna, sliced tomatoes, and black olives onto the bread.
Close the sandwich and get ready to enjoy!