Hi,
At Russian shops, they sell tins of cod liver.
At Chinese markets, they often have live fish. They kill and clean the fish before handing it off to the customer. The trick will be in convincing the guy to give you what you want. Between language barriers and disbelief (and potential legal issues??), it may take some patience to get it.
I once inquired how to cook a turtles at a Chinese grocery that had live turtles in tanks. I asked the same shop girl, "How to cook a turtle?"
Week 1: "They are sold as pets."
Week 2: "Old people eat them."
Week 3: I put the turtle in the cart, then went up to the very same girl, "How to cook a turtle?" She offered a detailed explanation.
Please report back on your experience.
Regards,