The secret to this salad lies in the consistent and fine dicing. Ideally, the cubes should be about 3–5 millimeters (smaller than common dice). This ensures all flavors combine in every bite and the salad is easily scooped into pita bread.
It's best to use Persian cucumbers or English cucumbers for the salad, as they have thin skin and few seeds. Tomatoes should be firm, ripe, and the watery interior should be removed to prevent the salad from becoming too soggy.
Slice the cucumbers and tomatoes lengthwise into thin planks, then cut them into strips. Next, dice the strips into the smallest, uniform cubes possible (approx. 3-5 mm size).
For tomatoes, it is recommended to remove the watery interior with seeds so the salad isn't too liquidy.
Dice the red onion and bell pepper (if using) into the same small cubes. Chop the onion even finer so its flavor is evenly distributed.
Finely chop the parsley.
Place all the chopped vegetables and parsley in a medium bowl.
In a small bowl, mix the olive oil and lemon juice. Pour the dressing over the salad, season with salt and pepper. Toss to combine.
Serve the salad immediately while the vegetables are fresh and crunchy. If you must prepare it in advance, chop and mix the vegetables beforehand, but add the dressing just before serving to preserve its texture.