put sliced red onion in a small bowl and fill with water and a sprinkle of salt. Let soak for 5 minutes (or more). Take out of water and pat dry. (If you like the taste of raw onions, skip this step!)
cube watermelon, chop mint and cucumber.
in a small mixing bowl combine lime juice (fresh or bottled) and salt. stir and set aside.
in a large mixing bowl combine arugula, watermelon, mint, feta, cucumber and dry onions.
add dressing and toss to mix.
top with flaky sea salt (optional). Serve as a vegetarian salad OR add grilled chicken and Enjoy!