Prep the ingredients. Chop the broccoli into small florets, dice the onion, and mince the garlic and ginger.
Stir together soy sauce, oyster sauce, rice vinegar, honey, and chicken broth in a small bowl.
Heat the pan. Place a large skillet over medium-high heat. Add 1 tablespoon oil. When it shimmers, add the broccoli and a pinch of salt.
Cook 3–4 minutes, stirring occasionally, until bright green and just tender. Transfer to a plate.
Sauté the aromatics. Add the remaining oil to the skillet, then the onion. Cook 2–3 minutes until softened.
Stir in garlic and ginger and cook 30 seconds until fragrant.
Brown the chicken. Add the ground chicken with a pinch of salt and pepper. Break it up with a spatula. Cook 5–7 minutes until no longer pink and lightly browned in spots.
Deglaze and season. Pour in the sauce mixture.
Scrape up any browned bits from the pan. Let it simmer 1–2 minutes.
Thicken (optional). If you like a glossy, clingy sauce, stir the cornstarch slurry (cornstarch mixed with water) into the pan. Simmer 1 minute until the sauce thickens slightly.
Add broccoli back. Return the broccoli to the skillet and toss to coat.
Cook another 1–2 minutes, just to warm through and marry the flavors.
Finish and serve. Turn off the heat. Stir in sesame oil and red pepper flakes. Taste and adjust salt, pepper, or a splash more soy sauce as needed.
Garnish with sesame seeds and green onions. Serve over rice or cauliflower rice.