It’s a thing in New Zealand, where they actually cook in the geothermal springs, done traditionally by Maori in the area that has geothermal activity(they also dig a hole sometimes, not sure if that depends on the tribe or just what they’re cooking). Apparently there’s a restaurant that does it too: whakarewarewa.com/experiences-traditional-food/

I haven’t tried it so can’t speak to the flavor, but Id imagine it would be somewhat sulphour flavoured, which doesn’t seem appealing, maybe it’s an acquired taste?