Cook rice according to package directions. I bought microwavable beans and steamed them right in the bag, but you can definitely boil or steam them until they're as tender as you wish. Chop your scallions.
Meanwhile, prep your chicken and add it to a large ZipLoc bag along with the cornstarch. Toss until coated.
Add the sauce ingredients (brown sugar, garlic, ginger, soy sauce, sriracha, and water) to a small bowl and whisk together.
Add the oil to a skillet, along with the chicken. Give it a stir and cook it over medium-high heat for a few minutes, stirring occasionally, until the chicken is no longer pink on the outside.
Pour the sauce into the skillet and reduce the heat to medium. Cook for a few more minutes until the chicken is cooked through and the sauce has thickened.
Divide the rice, green beans, and chicken evenly among your four containers. Garnish with scallions. I suggest reheating these bowls in the microwave.