Slice the onion and press the onion slices by hand with some salt so that the bitterness of the onion is reduced. Rinse the onion under cold water and squeeze to get rid of the excess water. Dice the tomatoes, cucumber and slice (dice) pepperones (bell pepper). Chop parsley and mint leaves finely.Put all the chopped vegetables in a salad bowl and mix well adding the salt. Add the lemon juice and olive oil dressing and toss well.

Tips:
You can add some crushed bell peppers to the dressing for a touch of spice. You can replace the lemon juice with vinegar. You can add a roasted, peeled and chopped eggplant to it which adds a distinct flavor to the salad.