Step 1
Whisk together the lime juice, scallion whites, serrano peppers, and salt in a large bowl. Allow rest for 5 minutes.
Step 2
Add in the watermelon, ½ cup of the cotija cheese, ¼ cup cilantro, ¼ cup pepitas, and the scallion greens, Stir to combine.
Step 3
In a small bowl, toss together the remaining cotija cheese, cilantro, and pepitas. Divide the watermelon mixture among serving bowls. Top with the reserved cotija mixture and serve immediately.