Peel and finely chop the red onion into small pieces, about 1/8 inch in size. Place it in a large mixing bowl.

Cut the Persian cucumbers in half lengthwise, and chop them into small, bite-sized pieces, about 1/4 inch thick. Add to the bowl.

Halve the Roma tomatoes, scoop out the seeds, and chop into small cubes. Add to the mixing bowl.

Squeeze the juice of one lemon into a small bowl, discarding any seeds. You're looking for about 2-3 tablespoons of juice.

Crush the dried mint and mix it into the lemon juice. Set aside.

Combine the chopped cucumbers, tomatoes, and onions gently in the mixing bowl. Pour the lemon-mint mixture over the vegetables and toss together.

Drizzle in olive oil before serving and season with salt and pepper to taste. Toss again to combine.