When sauteing chicken in either a stew or stir fry recipe, how can you judge if the chicken is cooked through?

I'm afraid that I am overcooking my chicken. Obviously the chicken needs to change from pink to white to be considered "done", but I've found that the chicken is not always entirely cooked through- to compensate for this problem I usually cut the chicken piece by piece while its still in the pan to determine if it is indeed cooked, however I know that such action is unnecessary and overly time consuming.