4 boneless chicken breasts, cut into bite-sized pieces
1/2 cup cornstarch
1/2 teaspoon salt
1/4 teaspoon black pepper
2 tablespoons vegetable oil
1/2 cup chicken broth
1/4 cup soy sauce
1/4 cup rice vinegar
2 tablespoons hoisin sauce
2 tablespoons brown sugar
2 teaspoons minced garlic
1 teaspoon minced ginger
1/2 teaspoon red pepper flakes
Green onions, sliced (optional for garnish)
Sesame seeds (optional for garnish)