In a food processor or blender, combine the tahini, greek yogurt, zest + juice of 2 lemons and the olive oil until smooth and combined. If needed thin with just a little water. Add the basil + a pinch of salt and pepper and the crushed red pepper flakes to the blender or food processor and pulse once more to combine.

In a medium bowl, gently combine the drained tuna with the olives and sun-dried tomatoes.

Cut the loaf of ciabatta in half lengthwise and then generously spread both halves with the basil tahini yogurt sauce. Now spread the tuna mixture over the bottom half of the ciabatta. Layer the following ingredients in a single layer: avocado, cucumber, hard boiled eggs, cabbage and arugula. Crumble the feta over the arugula and season with pepper. Add the top half of the ciabatta and gently push down on the sandwich to help it stick together.

From here, you can either wrap the sandwich in plastic wrap and place in the fridge for up to 1 day OR you can serve.

To serve, slice into 4 equal sandwiches and EAT!