This Soup Has Been Simmering for 45 Years

A perpetual stew, also known as forever soup, hunter's pot[1][2] or hunter's stew, is a pot into which whatever foodstuffs one can find is placed and cooked. The pot is never or rarely emptied all the way, and ingredients and liquid are replenished as necessary.[1][3] Such foods can continue cooking for decades or longer, if properly maintained. The concept is often a common element in descriptions of medieval inns. Foods prepared in a perpetual stew have been described as being flavorful due to the manner in which the ingredients blend together.[4] Various ingredients can be used in a perpetual stew such as root vegetables, tubers (onion, carrot, garlic, parsnip, turnip, etc.), and various meats.[3]

https://en.wikipedia.org/wiki/Perpetual_stew

I tried one of the world's oldest soups, a broth that's been kept simmering for 50 years by 3 generations of a family. It's now one of my favorite restaurants in Bangkok.