unity lookat only z pos

void LookZ()

    {

        var dir = Player.position - transform.position;

        Quaternion LookAtRotation = Quaternion.LookRotation(dir);

        Quaternion LookAtRotationOnly_Y = Quaternion.Euler(transform.rotation.eulerAngles.x, LookAtRotation.eulerAngles.y, transform.rotation.eulerAngles.z);

        transform.rotation = LookAtRotationOnly_Y;

    }