Wash cucumber and other vegetables under cold water. Dice them into bite-sized pieces.

Open canned tuna, drain liquid, then flake tuna into a large mixing bowl.

Combine Greek yogurt, olive oil, lemon juice, and Dijon mustard in a small bowl. Whisk until smooth and creamy.

Add diced vegetables and flaked tuna to the mixing bowl, then pour the dressing over and fold together.

Chop fresh dill and parsley, then fold them into the salad.

Cover the salad and chill in the refrigerator for 10-15 minutes before serving.