A simple, fresh watermelon salad says summer like nothing else. With the addition of crumbled feta cheese and a chunky olive dressing, the salty-sweet balance of this watermelon salad in particular is especially delicious. The secret to this Kalamata vinaigrette, which would be excellent with any blend of summer melons, is 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 the sweetness.
Process olives, walnuts, parsley, lemon zest, and 3 teaspoons of the lemon juice in a mini food processor until finely chopped, about 5 seconds. Transfer olive mixture to a small bowl, and whisk in 4 tablespoons of the olive oil until blended. Place watermelon on a baking sheet, and sprinkle evenly with 1/2 teaspoon of the salt.
Toss together arugula, and remaining 1 teaspoon lemon juice, 1 tablespoon olive oil, and 1/8 teaspoon salt in a medium bowl. Arrange arugula on a large platter. Nestle watermelon cubes in arugula mixture. Spoon olive mixture over watermelon; sprinkle feta and mint evenly over salad.