Liquamen is an ancient Roman fermented fish sauce. For a modern substitute, use fish sauce (such as nuoc mam) or a combination of soy sauce and a little vinegar. For a vegetarian version, use soy sauce and a pinch of salt as indicated in the ingredients.
Green beans cook faster than soybeans. Adjust simmering time accordingly to avoid mushy texture.
Coriander leaves (cilantro) should be added at the end to keep their bright flavor. If using ground seeds, they can be added with the cumin.