Combine rinsed sushi rice and 2 cups of water in a medium pot. Bring to a boil over medium-high heat, then reduce heat to low, cover, and let simmer for 20 minutes. Remove from heat and let cool slightly.

Press about 2 heaping tablespoons of the cooked sushi rice into each cup of a silicone muffin tin. Pack the rice firmly and refrigerate for 20 minutes to set.

In a mixing bowl, add chopped veggies, mukimame, and diced avocado. Drizzle in sauce and gently toss until combined.

Whisk together mayonnaise, sriracha sauce, honey, and sesame oil in a bowl. Adjust sriracha for desired heat.

Remove rice cups from the fridge and fill each with the veggie mixture. Drizzle spicy mayo over filled cups and sprinkle with black sesame seeds.