Said to have originated in hobo camps during the early 1900s, mulligan stew is a sort of catch-all dish of whatever is available. It usually contains meat, potatoes and vegetables in just about any combination. The name indicates that its origins might come from irish stewburgoo. The cook at a hobo camp responsible for putting this tasty concoction together was called a "mulligan-mixer."
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.