Instructions:
In a medium saucepan combine rice, salt, and 1¼ cups water. Bring to a boil, cover, then reduce heat to low and cook for 12 minutes. Take off heat and let sit, covered, 5 minutes more. Scrape rice onto a sheet pan in a thin layer and let cool completely.
In a medium bowl whisk to combine mayonnaise, miso, sriracha, and sesame oil. Add watermelon and green onion and toss to coat.
Divide rice between 2 bowls. Top with watermelon, cucumber, and avocado. Stick nori between the side of the bowl and the rice. If desired, drizzle bowls with more sriracha. Sprinkle with sesame seeds.