Cook rice according to package directions, adding a pinch of salt.
Steam broccoli until crisp-tender, about 5 to 6 minutes. Drain and set aside.
Combine cornstarch, pepper, and 1½ teaspoons salt in a large bowl.
Add chicken and toss to coat.
Heat tablespoon of vegetable oil in skillet set over high heat.
Add chicken and cook, turning occasionally, until lightly browned and cooked through, about 5 minutes.
In a medium bowl, combine honey, soy sauce, vinegar, Sriracha, garlic, ginger, sesame oil, teaspoon of sesame seeds, and pinch of salt.
Add to skillet and let reduce for about 1 minute.
Add chicken back to skillet and cook, tossing occasionally, until sauce is reduced and coats chicken, about 2 minutes.
Fold in broccoli and remove from heat.

Serve chicken and broccoli with rice.
Garnish with sesame seeds and onion ( if using )