My wife is from Argentina and here in Phoenix we tried everywhere find the Argentine foods including Ranch Market, Food City, various small latin markets throughout the city and weren't able to find the things we needed. That is until we found Lee Lee Supermarket in Chandler. They definitely have most of the big Argentinean foods including many brands of mate, all the empanada dough (La Saltena/Goya), dulce de leche etc. Good find, just wish it was a bit closer to where we live. They also have quite a few products from Brazil and many other countries.
Lee Lee Supermarket