Cucumbers add a welcome crunch to this refreshing summer salad of cubed watermelon, fresh herbs, and crumbled feta cheese. You can replace the fresh mint with basil if you prefer, or use a combination of both herbs. A personal-sized seedless watermelon is just the right size for this salad, but you can also use pre-cut melon or a portion of a larger watermelon. Be sure to dress the salad right before serving it to prevent the melon and cucumbers from watering down the vinaigrette
Combine watermelon, cucumber, and feta in a large bowl; set aside.
Combine vinegar, shallot, lemon juice, thyme, salt, and pepper in a medium bowl. Slowly drizzle in oil, and whisk until emulsified. Toss watermelon mixture with 1/2 cup of the dressing. Transfer to a serving platter, and drizzle with remaining dressing. Sprinkle with mint leaves before serving.