Combine all the ingredients, then slowly add the olive oil, lime juice, salt and pepper. Toss well and taste for seasoning.
Continue adding the oil, lime juice, salt and pepper, tossing between each addition, until seasoned to taste.
To prepare in advance, combine all of the ingredients except the watermelon, lime juice, olive oil, salt and pepper. Can be prepared up to 4 hours in advance and refrigerated.Even if serving right away, the combined ingredients short of the watermelon, dressing/seasonings and feta can be stored in the refrigerator for 30 minutes to enhance the freshness factor. But this step is optional.