01 - Place watermelon cubes, diced cucumber, sliced red onion, and chopped mint into a large mixing bowl.
02 - In a small mixing bowl, whisk together the extra-virgin olive oil, freshly squeezed lime juice, sea salt, and black pepper until emulsified.
03 - Pour the prepared dressing over the salad ingredients and gently toss with a large spoon to coat evenly.
04 - Immediately before serving, sprinkle crumbled feta cheese on top, if using.
05 - Transfer salad to serving bowls and present immediately for optimal texture and flavor.