Slice the tomatoes in big and small pieces for a more dramatic salad. For best results, make the salad without ever refrigerating the tomatoes, but with the watermelon ice cold from the refrigerator. The contrast of temperatures will give the salad an extra fresh taste. You will need Mozzarella in the "bag" with liquid; the liquid is used in the dressing.
For the dressing: In a bowl, whisk together the olive oil, mozzarella liquid and pickle juice. Whisk in the vinegar. Taste for seasoning. Set aside.
For the herb salt: Put the parsley and the salt in the bowl of the food processor and pulse to blend until they are integrated and the salt is green. Keep in a sealed jar.
To assemble the salad: Slice and arrange the tomatoes in a single layer on a flat surface. Drizzle the tomatoes with a little sugar, black pepper and the dressing. Top with a sprinkle of the parsley salt. Taste a tomato slice for seasoning. Squeeze the lemon juice on the watermelon. Season the mozzarella slices with parsley salt and a little dressing, as well. Arrange the tomatoes, mozzarella and watermelon cubes on 6 rectangular plates. Serve immediately.