A bean pie is a pie made, as the name would seem to suggest, with beans that have been mashed or pureed. Classically, bean pie is made as a custard pie, much like pumpkin or sweet potato pie, and the dish is often associated with the American South and with the soul food culinary tradition.lassically, bean pie is made as a custard pie, much like pumpkin or sweet potato pie, and the dish is often associated with the American South and with the soul food culinary tradition.