So simple yet somehow so elegant, tacos al pastor might not have come from the Aztecs, but these scrumptious delights are the signature street food of Mexico, and it's easy to see why.

Forget whatever mutations the taco has taken (for better or worse), there is nothing more authentic than a warm corn tortilla cradling pork that has been marinated in dried chilies, spices and pineapple, which makes the meat even more tender. After being slow-cooked on a vertical spit, or trompo, the pork is adorned with some fresh, finely chopped onions and cilantro, and the whole thing is topped with a picture-perfect slice of pineapple, artfully cut and dropped from the top of the trompo.

While there is some debate over the origins of tacos in general, tacos al pastor are said to be Lebanon's gift to Mexico after Lebanese immigrants in the 1930s provided the vertical spit used to make shawarma. Mexican taqueros switched out lamb for pork with local spices, added the pineapple to cut in some sweetness, and a new national delicacy was born.

It all seems so simple, yet even famed Mexican food chef Rick Bayless can't figure it out.

"I am not sure what it is — the pineapple, the combination of the onion, not sure," he wrote for Epicurious.com in 2007, noting that he has never done a real recipe, especially because the layering of the thin pork meat on the vertical spit is difficult to achieve.

Thankfully, many taqueros out there — and more and more restaurateurs in the United States — have figured it out for us.

So simple. So sweet. So perfect. And they should cost you only a few pesos.