Finely slice the red onion and rub with salt, leave to rest aside. Cut the avocado in half, take out the core and sprinkle the pulp with lemon juice.
Prepare a tzatziki sauce by combining the greek yogurt, the minced garlic clove, the dill and a tsp of lemon juice.
Cut the cucumber, the carrot, the red cabbage and the avocado in long thin slices.
Lay a tortilla wrap and add half of the rucola and half of the cabbage. Then add half of each: the cucumber, the avocado, the carrot, the red onion, the tuna and the olives. Pour half of the tzatziki sauce over the tuna.
Wrap the small ends of the tortilla inwards, then roll the remaining lateral edges so they overlap in the end. Squeeze the wrap a little to make it more compact and secure the wrap if needed with 2 small toothpicks.
Repeat the process with the remaining wrap and ingredients and enjoy!