Nothing says summer quite like watermelon, and this salad has all the right flavors to complement it. Juicy watermelon chunks are dressed with lime juice for an unbelievable sweet/tart pairing. Nutty arugula and savory onion hints from the nigella seeds add a hint of savory crunch. And because my crowd is always game for a little extra summer heat, a sprinkle of Marash chile flakes round out the finish. This salad is easy to whip up for a weeknight side dish and scales up nicely for a crowd pleasing BBQ or picnic.