Marinate the chicken: In a bowl, toss chicken with 1 tablespoon cornstarch, soy sauce, and a pinch of pepper. Let it sit for 10 minutes while you prep the sauce.
Mix the sauce base: In a measuring cup, combine orange juice, orange zest, rice vinegar, honey, broth, and sriracha if using. Taste and adjust sweetness or tang.
Sear the chicken: Heat oil in a large nonstick skillet over medium-high.
Add chicken in a single layer and cook 2–3 minutes per side until lightly browned and just cooked through. Remove to a plate.
Sauté aromatics: In the same pan, reduce heat to medium. Add garlic and ginger, stirring for 30 seconds until fragrant.
Build the sauce: Pour in the orange sauce base.
Bring to a simmer and cook 2–3 minutes to meld flavors.
Thicken: Stir in the cornstarch slurry. Simmer 1–2 minutes, stirring, until glossy and slightly thickened.
Combine: Return chicken and any juices to the pan. Toss to coat and cook 1–2 minutes until the sauce clings and the chicken is hot.
Finish and serve: Season with salt and pepper if needed.
Garnish with green onions and sesame seeds. Serve with steamed broccoli and a small portion of brown rice or cauliflower rice.