1In a small bowl, combine feta cheese, Greek yogurt, green onion and oregano. Season generously with pepper.
2In another bowl, combine the vegetables and olives.
3Spread the yogurt-feta mixture evenly over each tortilla.
4Garnish with vegetables over the entire surface of the tortilla. Add a few spinach leaves on top and roll up, squeezing gently.
5Repeat the operation for each tortilla.
6Wrap the rolls in cling film and refrigerate from 30 minutes to several hours.
7Unpack each roll and, using a sharp knife, gently cut into equal pieces (about 8-10).
8Stick with toothpicks if necessary.