Salt in the dressing and cheese heightens the sweetness of the watermelon.
Combine first 6 ingredients in a large bowl; toss gently. Combine lemon rind, lemon juice, oil, and salt in a small bowl, stirring with a whisk. Pour juice mixture over watermelon mixture; toss gently to coat. Sprinkle with cheese.
Wine note: The sprinkling of salty Parmigiano-Reggiano provides just the right counterpoint to all the ripe watermelon flavors in this refreshing salad. A great wine match will pick up on the watermelon flavors and stand up to the cheese at the same time, and only one type of wine will do it: rosé. Choose a rosé with bright watermelon flavors like Robert Hall Winery Rosé de Robles 2005 from Paso Robles, California ($14). --Karen MacNeil