Begin by cutting the chicken breast into bite-sized pieces, ensuring uniformity for even cooking.

In a mixing bowl, combine the cut chicken with soy sauce, minced garlic, and ginger. Toss together and let marinate for about 10 minutes.

Heat a tablespoon of vegetable oil in your skillet or wok over medium-high heat. Add the marinated chicken and cook for 5-7 minutes, stirring occasionally, until browned.

Stir in the broccoli florets and cook for an additional 3-4 minutes.

In a separate bowl, mix cornstarch with a small amount of water until smooth. Pour this mixture into the skillet, stirring gently to combine. Cook for about 2 minutes until the sauce thickens.

Serve the stir-fry over bowls of steamed rice, ensuring each serving is generously topped with the sauce.