Preheat the oven to 425°F (220°C) and position the rack on the top level. Grease a large sheet pan with olive oil or line it with parchment paper.

Prepare the coconut rice. In a medium skillet over medium-high heat, add sesame oil and sesame seeds. Toast for 1-2 minutes until golden. Add the rinsed rice, coconut milk, water, and a pinch of salt. Stir and bring to a boil. Once boiling, cover, reduce heat to low, and simmer for 15-18 minutes until the liquid is absorbed and the rice is fluffy.

Make the meatballs. In a large bowl, combine breadcrumbs and milk. Let sit for 5 minutes to soften. Meanwhile, chop the scallions, reserving the green ends for garnish. Add the ground beef, scallion whites, ginger, garlic, salt, and red pepper flakes (if using) to the breadcrumb mixture. Mix well with your hands until fully combined.

Using a large cookie scoop, form 1 1/2-inch meatballs and place them on one side of the prepared baking sheet. On the other side, arrange the trimmed green beans, drizzle with 1 tablespoon olive oil, sprinkle with salt, and toss to coat. Drizzle the remaining 2 tablespoons of olive oil over the meatballs.

Bake on the top rack for 14-16 minutes, or until meatballs reach an internal temperature of 165°F (74°C) and green beans are browned and tender.

Prepare the firecracker sauce. In a medium bowl, mix all sauce ingredients until well combined. Adjust the heat level by adding more Sriracha or chili flakes to taste.

Fluff the coconut rice and divide it into bowls. Top with meatballs, green beans, and a generous drizzle of firecracker sauce. Garnish with reserved green onions, sesame seeds, and chili flakes or crunch for added texture.