"Tastes just like chicken!"
Nearly every culture invents a food that is
weird or disgusting to outsiders. These are cultural markers that show who's a member (they like it) and who's not a member (they gag.) Maybe a group of kids started eating it on a dare and at some point, everyone in the community accepts it. They then perpetuate it (perpetrate it) on the next generation. Then they nudge each other and laugh when foreigners gasp.
http://www.weird-food.com/The links are all on the left. Bon appetit