Prep the chicken: Pat the chicken dry with paper towels. Season lightly with salt and pepper.
This helps browning and keeps the meat juicy.
Make the sauce: In a small bowl, whisk cornstarch with chicken broth until smooth. Stir in soy sauce, rice vinegar, honey (if using), and a pinch of black pepper. Set aside.
Cook the broccoli: Heat 1 tablespoon oil in a large skillet over medium-high heat.
Add broccoli and a big pinch of salt. Cook 3–4 minutes, stirring, until bright green and crisp-tender. Transfer to a plate.
Brown the chicken: Add the remaining 1 tablespoon oil to the skillet.
Add chicken in a single layer. Cook 5–7 minutes, stirring occasionally, until lightly browned and cooked through.
Add aromatics: Reduce heat to medium. Stir in garlic, ginger, and red pepper flakes.
Cook 30 seconds, just until fragrant—don’t let the garlic burn.
Sauce it up: Whisk the sauce once more, then pour it into the pan. Simmer 1–2 minutes, stirring, until slightly thickened and glossy.
Finish with broccoli: Return broccoli to the skillet and toss to coat. Turn off the heat and stir in toasted sesame oil for a final nutty note.
Taste and adjust salt, pepper, or soy sauce as needed.
Serve: Garnish with sesame seeds and green onions if you like. Serve over brown rice, cauliflower rice, quinoa, or enjoy it on its own for a lower-carb meal.