There are a couple of ways to stuff chicken breasts. One is to pound them flat, spread the filling over the top, then roll them into pinwheels. For this stuffed chicken, a pocket is cut horizontally through one side of the chicken to make an internal space for the filling to reside. It's important to only make one opening and keep the other sides intact. Plus, it's key to seal the pocket with a toothpick or by wrapping the chicken with a slice of ham so the filling does not ooze out as it cooks.