What common herb is known as the base of the "Holy Trinity" in Cajun cooking?

The common herb known as the base of the "Holy Trinity" in Cajun cooking is celery. The "Holy Trinity" consists of three key ingredients: onions, bell peppers, and celery. This combination serves as a flavor foundation for many Cajun and Creole dishes, much like the mirepoix does in French cuisine.

Celery plays a crucial role in this mix by adding a subtle flavor and aromatic depth to various recipes, including gumbo and jambalaya. While other herbs and vegetables like thyme, parsley, and basil are also used in Cajun cooking, they do not form part of the foundational trio that defines the "Holy Trinity." Understanding the significance of ingredients like celery helps to appreciate the unique characteristics of Cajun cuisine and the importance of flavor layering in cooking.