Pottage is a term for a thick soup or stew made by boiling vegetables, grains, and, if available, meat or fish. As explained in The Oxford Companion to Food, it was a staple food for many centuries. The word pottage comes from the same Old French root as potage, which is a dish of more recent origin.
Pottage commonly consisted of various ingredients easily available to serfs and peasants, and could be kept over the fire for a period of days, during which time some of it could be eaten, and more ingredients added. The result was a dish that was constantly changing. Pottage consistently remained a staple of the poor's diet throughout most of 9th to 17th-century Europe. When wealthier people ate pottage, they would add more expensive ingredients such as meats. The pottage that these people ate was much like modern-day soups. This is similar to the Welsh cawl, which is a broth, soup or stew often cooked on and off for days at a time over the fire in a traditional inglenook.
In Nigeria the words pottage and porridge are synonymous, and such foods are consumed as a main meal. Nigerian yam pottage/porridge includes tomatoes and other culinary vegetables along with the yam. It may also have fish and/or other meat.
In the King James Bible translation of the story of Jacob and Esau in the Book of Genesis, Esau, being famished, sold his birthright (the rights of the eldest son) to his twin brother Jacob in exchange for a meal of "bread and pottage of lentiles" (Gen 25:29-34). This incident is the origin of the phrase a "mess of pottage" (which is not in any Biblical text) to mean a bad bargain involving short-term gain and long-term loss.
Pottage was typically boiled for several hours until the entire mixture took on a homogeneous texture and flavour; this was intended to break down complex starches and to ensure the food was safe for consumption. It was often served, when possible, with bread.