Whisk orange juice, soy sauce and cornstarch in small bowl until the starch dissolves.
Season both sides of the chicken with salt and pepper and then dredge lightly in flour.
Heat oil over medium-high heat and cook chicken, turning once, 10 minutes or until chicken is cooked through. Remove from skillet and keep warm.
Add the broccoli to the skillet, mix and cook, stirring occasionally, 5 minutes or until vegetables are crisp-tender. Add the garlic and ginger and cook 1 to 2 minutes or until just fragrant. Stir in the orange juice mixture, orange zest, chicken stock and rice wine vinegar. Cook, stirring occasionally, for 3 minutes or until sauce is bubbly and starts to thicken.
Add the chicken back to pan and let the flavors combine for 1 to 2 minutes before serving. Sprinkle with cilantro.
Recipe by Go Dairy Free at https://www.godairyfree.org/recipes/light-orange-chicken-broccoli-stir-fry