Re: Basel - Peruvian restaurants?
The food scene in Basel is rather homogenous. I don't believe there is a Peruvian place (although I would gladly be corrected).
As for South American markets, I have two ideas for you.
One is a store on the corner of Clarastrasse and Hammerstrasse. It looks like a hair products store, but at the back is great little food section. It is primarily Caribbean and African specialties, but there is some South American stuff there as well.
The other is El Sol in Allschwill. They are primarily mail-order only (elsol.ch), but they are open for drop-in customers on the last Saturday of every month.
There are other options in ZH but they have been discussed at length on this forum.