This is a question that has come up before a long time ago, I am 1/8th Native American myself and I think I have the right to speak for my tribes even though I am about as white as they come.
The short answer is that Native Americans are not one group in the least. You have have tribes ranging from the Inuit to the South American rain forest-tribes. They are completely scattered in geography and environment so there is no way to have an ‘authentic’ Native American meal. The tribes on the coastal Northeast ate a lot of seafood because it was easy to get while the central tribes ate buffalo and whatever else they could find on the prarie.
However, there is some Native American food that is common. It is called Mexican even if there are many variations on that. Some people claim that you can’t have ‘authentic’ Mexican foods in the U.S. in places like Texas or California because they aren’t currently a part of Mexico. That is the dumbest answer you can possibly give because they were Mexican up until fairly recent history and still have a huge influence from the culinary styles from corn based tortillas to burritos. That is about as Native American as you can get without faking it.
There is a huge misconception that food preferences are longstanding across any cultures when that isn’t true at all. Most of them last less than 50 years even in longstanding cultures and even archetypal foods in Europe are rather recent. For example, both the potato and tomato were only introduced to Europe after the New World voyages and yet they transformed the culinary style of both Ireland and Italy among many others.
You wouldn’t want to pay for a generic authentic Native American meal in a restaurant. It would be really bland. Most of the tribes didn’t use many spices at all so it would just taste like BBQ meat with nothing added or whatever they could gather in the form of berries or nuts.