Pour the chicken broth or chicken stock into a medium saucepan.
Place the saucepan over medium-high heat.
Bring the broth to a boil.
In a small bowl, combine the cornstarch with a small amount of cold water.
Stir until the cornstarch mixture is smooth and thick.
Slowly add the cornstarch mixture to the boiling broth while stirring continuously.
Continue stirring until the broth begins to thicken into a gravy.
Reduce the heat to medium-low.
Add the shredded cooked chicken breast to the thickened gravy.
Stir until the chicken is evenly coated with the gravy.
Continue cooking and stirring until the gravy is thickened and the chicken is heated through.
Season with salt and black pepper to taste.
If the gravy is too thick, add a small amount of chicken broth or water and stir until the desired consistency is reached.
If the gravy is too thin, simmer briefly while stirring until thickened.
Warm the waffles, bread, or mashed potatoes before serving.
Spoon the hot chicken gravy over the waffles, bread, or mashed potatoes.
Serve immediately while warm.