If all you want to say is "Yes, yes, continue conducting yourself in this bad manner and you will see what I will do to you," then you're going to need "head raised and bent forward several times, with the eyes narrowed and menacing." If, however, the situation is more grave, if what you mean is "Wait, or give me time, so that a favorable occasion might turn up and then I will make you see if I know how to avenge myself for the wrong you do to me," then "palm held facing downwards and oscillated slowly up and down" is the ticket.

From Joan Acocella "The Neapolitan Finger", being a NYRB review of Gesture in Naples and Gesture in Classical Antiquity by Father Andrea de Jorio.