Mix the dressing in a medium bowl and add the cucumbers, onions, and tomatoes. Toss to combine. Let them marinate for a few minutes while you cut up the melon.
Chop the melon into slices and then cubes or scoop it with a melon baller. Gently fold the melon into the rest of the salad.
Garnish with the fresh mint and salt and pepper to taste.
This salad is great made ahead and refrigerated for a few hours, as it allows the flavors to meld. (I wouldn’t make it more than 8 hours ahead though).
Notes
This salad is yummy without the oil too, feel free to leave it out or add feta cheese or nuts as a garnish.