Both aztecs and their rivals were decimated by disease, that was the key. Given time, they would have been able to master horse riding, armor and more modern weapons, as they actually did in one of the last battles in Xochimilco just a year after the fall of Tenochtitlan, but too few remained to make a difference.

I feel a Mexican torta ahogada could qualify if we keep the definition of soup flexible, too.

Whack the pit with another knife