In many cultures, eating eyeballs is a food taboo but not so in Mexico. If you’ve already done all the traditional tacos, try an unlikely combination of cheeks, brains and eyes, piled on a tortilla and smothered in cilantro and onion. Eating this portion of brains and eyes does not guarantee that you’ll be smarter or see any better. Savor every bite. If you swallow it too quickly, you'll miss the nuances.