Tag out door sous vide

Help needed on “natural sous vide”

Eggs boiled in onsen (japanese: hotspring), Nagano, Japan (Photo: Miya.m. Permission: GFDL, cc-by-sa-2.1-jp). In Japan eggs cooked in hot springs (onsen) are known as onsen tamago. I’ve also read that Māori women used boiling pools at Whakarewarewa to cook. In…