Prepare Your Ingredients: Wash and cut the broccoli into bite-sized florets and slice chicken breasts into thin strips. Set aside.

Marinate the Chicken: Combine chicken, soy sauce, ginger, and garlic in a bowl. Mix thoroughly and marinate for at least 15 minutes.

Cook the Chicken: Heat skillet over medium-high heat, add vegetable oil, add marinated chicken, stir-fry for 5 minutes until golden brown. Remove chicken.

Stir-Fry the Broccoli: In the same skillet, add more oil if needed and stir-fry broccoli for 3 minutes until vibrant and tender-crisp.

Prepare the Sauce: In a bowl, whisk together cornstarch, brown sugar, remaining soy sauce, and chicken broth until smooth.

Combine Everything: Return chicken to skillet, pour sauce over, toss gently and cook for an additional minute until thickened.