Sadly it seems most of the Native pre-Colombian foodways are long gone (in the U.S. at least). There's some wonderful exceptions though, lots of Tex-Mex style foods are direct descendants of native foods. The foods that are kept as Native foods in many areas are often created out of the hardships that came post-Colombian, and often post resettlement.
For example, I spent some time in the Navajo nation and one of the main traditional foods is Frybread -- a tradition that started after resettlement when lard and flour were brought in by the U.S. government to fend off starvation -- and is common on other reservations as well. There's some decent hearty food that's since been built off of fry bread. Is it "Native food?" Or is it food made by Native Americans, who often are trying to modernize folkways and tap into locally available ingredients?
To be honest, pretty much everywhere is post-Colombian now. You can get tomatoes, peppers, corn, squash, and potatoes (among other things) pretty much anywhere on the planet. And the converse is true, as the mass of Euro-Asian-African foodways have spread across the Americas just as well.
Some videos of native foods from the Cherokee people, a tribe that's been putting tremendous efforts into preserving their language, and culture. A few people have even been identified as Cherokee national treasures for their traditional food knowledge.