Cook rice according to package directions and set aside.
Cut chicken into bite-size pieces, season with salt, pepper, and garlic powder, then toss with cornstarch until lightly coated.
Heat olive oil in a large skillet over medium-high heat. Add chicken and cook for 6–8 minutes, stirring occasionally, until cooked through and lightly golden.
In a small bowl, whisk together soy sauce, honey, rice vinegar, garlic, ginger, sesame oil, and sriracha (if using).
Pour sauce into the skillet with the chicken and stir to coat. Simmer for 2–3 minutes until the sauce thickens and becomes sticky. Add a splash of water if the sauce gets too thick.
Assemble bowls by adding rice to each bowl, topping with sticky chicken, veggies, green onions, and sesame seeds. Serve immediately.