Wash the tomatoes, cut them into small pieces as you like and put them in a bowl. Pour some sea salt over the tomatoes and let it steep for a few minutes.
In the meantime, peel the cucumbers, cut them into small pieces and add them to the tomatoes. Also cut the feta cheese into small cubes and add to the tomatoes and cucumber.
For the dressing, peel and chop the onion and place in a small bowl. Add the olive oil and vinegar, season with pepper, oregano and thyme to taste and mix.
Then add the dressing to the tomatoes, cucumber and feta cheese and mix the whole salad well.
It is advised to let the lettuce steep for about 6 hours before consumption to allow the spices to work properly.