Arrange an oven rack in the middle and preheat the oven to 425°F. Line a large rimmed baking sheet with parchment or foil and brush or rub the surface with the neutral oil so pieces won’t stick.
In a medium bowl toss the chicken pieces with the beaten egg white until evenly coated. Add the cornstarch and 1 teaspoon of the kosher salt and toss again until each piece is lightly dusted; shake off excess cornstarch.
Spread the chicken in a single layer on one side of the prepared sheet pan, leaving the other half for the broccoli. On a separate bowl, toss the broccoli florets with the toasted sesame oil, remaining 1/2 teaspoon kosher salt and a pinch of black pepper; place on the empty side of the sheet pan.
Roast in the preheated oven for 14 minutes. Use tongs to flip the chicken pieces (and give the broccoli a stir), then return the pan to the oven and roast another 8 minutes, or until the chicken reaches 165°F and the broccoli is tender with some browned edges.
While the proteins and veggies roast, whisk together the honey, sriracha, rice vinegar, 1 teaspoon sesame oil and grated ginger in a bowl until smooth and slightly loose. Taste and adjust heat or sweetness as needed.
When the chicken and broccoli come out of the oven, transfer the chicken to a clean bowl and pour the honey-sriracha glaze over it. Toss to coat every piece. Spread coated chicken back on the pan and place under the broiler 1 to 2 minutes to caramelize the glaze — watch closely so it doesn’t burn.
Divide the warm brown rice among 4 bowls, top with roasted broccoli and the glazed chicken. Sprinkle scallions and sesame seeds over each bowl. Let bowls rest 3–5 minutes so the sauce sets slightly, then serve.
To meal-prep: let components cool completely before sealing in containers. Reheat in the microwave until hot, or warm in a skillet to refresh the glaze.