Eat humble pie
Act in a submissive and apologetic manner, especially after committing a transgression, dates from the early 19th century but it all starts from the mid-1400s when umbles or humbles referred to offal or cheap cuts of meat, especially deer. By the mid-17th century, umble or humble pies (humble was simply an alternative spelling of umble and had nothing to do with humble as in meek) made from such cuts of meat, were eaten by poor, low class people but by the early 19th century umble pie had become humble pie and acquired its current figurative meaning. There is a strong element here of what is known in etymology as catachresis, which is the supplanting of one word for another that sounds similar. The expression to eat humble pie probably came about because people thought that those eating umble pies were merely dropping their aitches and so changed it to humble pie. Plus, of course, the fact that being humble is often associated with being poor, as in humble beginnings.