Open the tuna cans and let the juice drain.
Clean the vegetables and cut the spring onion crosswise into fine rings.
Core the peppers, cut them into strips and then dice them finely.
First cut the celery in half, then cut lengthwise into fine strips and then dice crosswise.
Peel the cucumber, then cut it in half and scrape out the seeds with a small spoon. Then cut lengthwise into strips and dice crosswise.
Peel the garlic clove and either press or chop it finely.
Peel the eggs and dice them finely.