In a large mixing bowl, whisk together ¼ cup of olive oil, 2 tablespoons of balsamic vinegar, a pinch of salt, and freshly cracked black pepper. Add 2 tablespoons of finely chopped fresh mint and whisk until well combined and emulsified.

Cut the watermelon into bite-sized cubes, slice ½ of a red onion and half an English cucumber. Add these ingredients to the bowl with the dressing and gently toss.

Crumble about ¾ cup of feta cheese into the salad, sprinkling it on top. Mix gently to combine.

Transfer the salad to a serving dish and garnish with extra mint leaves before serving.