Dice/ slice the cucumber. Place them on a plate.
Add salt to them and mix.
Allow to rest for 15 minutes to release excess water.
Take out the slices/ pieces and place them on a clean plate and wipe with a kitchen napkin.
Then dice the tomatoes, red onions, parsley leaves, basil leaves and place them in the mixing bowl. Add the cucumber.
In a small jar, add red wine vinegar, extra virgin olive oil, minced garlic, oregano, salt, and pepper. Close the lid of the jar and shake for 15 - 20 seconds till it's mixed.
You can also use your blender or food processor to blend them nicely. In such a case, add your herbs to it too.
Then pour the sauce over the diced cucumber, tomato, onion. Toss well to combine.