You have answered your question by coming to this place with your enquiry. There is an amazing spectrum of experts at /r/Askhistorians, and if your question isn't perfectly suited here, there is usually someone to suggest another subreddit. Before reddit, finding the experts you seek was more difficult. Before Google, it was extremely difficult. You are fortunate to have this resource. Use it! And please send me some mead.

Apart from searching on /r/AskHistorians, you could take the more traditional path (I think it could be more successful) and look for publications on your subject. I'm not at all familiar with your exact topic, but you might search for books and articles, maybe even conference announcements and reports about Aztec culture, south american food and so on. Try using catalogues of big libraries (Library of Congress, British National Library, maybe a Meta Search like the KVK: http://www.ubka.uni-karlsruhe.de/kvk_en.html), for an easier access try Google Books and Amazon, and please do not forget to search for articles, most easily via JSTOR. You may not be able to read those articles due to license restrictions, so set your search to show everything, not only those articles you can access. Try looking at the (freely available) first page if it fits you in any way, and then google-search the author. He or she may have a good profile page on their university's server, including a CV and a list of all publications. If you have a feeling that they're a match, send them an e-mail. I can only speak from my own experience, but messages from people outside of my field asking questions about it always make me happy.