A simple, fresh watermelon salad says summer like nothing else. And with the addition of crumbled feta cheese, bright mint, and a chunky olive vinaigrette, the salty-sweet flavor balance of this watermelon salad is especially swoon-worthy. The secret to the salad's Kalamata dressing, which would be excellent with any blend of summer melons, is in the toasted walnuts. The robust nuts temper the intense brininess of the olives to just the right level, while also giving the dressing another layer of rich flavor. If you’re hesitant about salting your watermelon, just trust us on this one—sprinkling the juicy summer fruit with salt actually amps up its sweetness.