Step 1

Cut white and light green parts of scallions into 2-inch pieces and set aside in a small bowl. Thinly slice the remaining dark green parts of the scallions and reserve for topping.

Step 2

Combine soy sauce, mirin, brown sugar, 2 teaspoons cornstarch and 1/2 teaspoon pepper in a small bowl; set aside. Toss chicken with the remaining 1 teaspoon cornstarch and 1/4 teaspoon pepper in a large bowl.

Step 3

Heat 1 tablespoon oil in a large nonstick skillet over medium-high heat. Add the chicken; cook, stirring occasionally, until golden brown and cooked through, about 5 minutes. Transfer to a plate.

Step 4

Heat the remaining 1 tablespoon oil in the skillet over medium-high heat. Add broccoli, bell pepper and 2-inch scallion pieces; cook, stirring often, until the vegetables are tender-crisp, about 2 minutes. Return the chicken to the pan and stir in ginger and the reserved soy sauce mixture. Cook, stirring often, until the sauce thickens and coats the chicken, 4 to 5 minutes.

Step 5

Divide rice evenly among 4 bowls. Top with the chicken and vegetable mixture and the reserved sliced scallions; garnish with sesame seeds, if desired.