In a medium pot, combine rinsed rice and water. Bring to a boil over high heat. Reduce the heat to low, cover, and simmer for 20 minutes or until the rice is cooked and water is absorbed. Remove from heat and let it cool slightly.
Press about 2 heaping tablespoons of cooked rice into each cup of a muffin tin. Press down to compact the rice. Place the muffin tin in the fridge and chill for 20 minutes, allowing the rice to set.*
In a mixing bowl, combine chopped veggies, steamed edamame, diced avocado, and coconut aminos or soy sauce. Mix well to combine the flavors.
In another bowl, whisk together all mayo ingredients. Adjust the Sriracha sauce to your desired level of spiciness.
Remove the rice cups from the fridge. Spoon a heaping tablespoon of the veggie filling over each rice cup. Drizzle spicy mayo over the top of the veggies and garnish with black sesame seeds.