Trim excess fat from chicken breasts and cut into 1-inch cubes. Toss chicken pieces in a mixture of cornstarch, salt, and pepper.

Heat vegetable oil in a skillet, add chicken cubes and cook until golden brown, about 3 minutes on each side. Remove and set aside.

In the same skillet, add minced garlic and sauté for 30 seconds.

Combine water, soy sauce, apple juice, chicken broth, ketchup, bourbon, vinegar, brown sugar, ginger, onion powder, and pepper flakes. Stir and bring to a boil.

Return chicken to the skillet, lower heat, and simmer for 10-15 minutes to thicken the sauce.

Serve over rice or with broccoli. Garnish with green onions or sesame seeds if desired.