The holy trinity is the Cajun

Cajun cuisine

Cajun cuisine is the style of cooking named for the French-speaking Acadian or "Cajun" immigrants deported by the British from Acadia in Canada to the Acadiana region of Louisiana, USA. It is what could be called a rustic cuisine — locally available ingredients predominate, and preparation...

 and Louisiana Creole

Louisiana Creole cuisine

Louisiana Creole cuisine is a style of cooking originating in Louisiana which blends French, Spanish, Portuguese, Italian, Greek, Asian Indian, Native American, and African influences, as well as general Southern cuisine...

 variant of mirepoix

Mirepoix (cuisine)

A mirepoix is a combination of celery , onions, and carrots. Mirepoix, either raw, roasted or sautéed with butter, is the flavor base for a wide number of dishes, such as stocks, soups, stews and sauces...

: onion

Onion

The onion , also known as the bulb onion, common onion and garden onion, is the most widely cultivated species of the genus Allium. The genus Allium also contains a number of other species variously referred to as onions and cultivated for food, such as the Japanese bunching onion The onion...

s, bell pepper

Bell pepper

Bell pepper, also known as sweet pepper or a pepper and capsicum , is a cultivar group of the species Capsicum annuum . Cultivars of the plant produce fruits in different colors, including red, yellow, orange and green. Bell peppers are sometimes grouped with less pungent pepper varieties as...

s, and celery

Celery

Apium graveolens is a plant species in the family Apiaceae commonly known as celery or celeriac , depending on whether the petioles or roots are eaten: celery refers to the former and celeriac to the latter. Apium graveolens grows to 1 m tall...

 in roughly equal quantities. This mirepoix is the base for much of the cooking in the regional cuisines of Louisiana

Louisiana

Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

. Variants use garlic

Garlic

Allium sativum, commonly known as garlic, is a species in the onion genus, Allium. Its close relatives include the onion, shallot, leek, chive, and rakkyo. Dating back over 6,000 years, garlic is native to central Asia, and has long been a staple in the Mediterranean region, as well as a frequent...

, parsley

Parsley

Parsley is a species of Petroselinum in the family Apiaceae, native to the central Mediterranean region , naturalized elsewhere in Europe, and widely cultivated as an herb, a spice and a vegetable.- Description :Garden parsley is a bright green hairless biennial herbaceous plant in temperate...

, or shallot

Shallot

The shallot is the botanical variety of Allium cepa to which the multiplier onion also belongs. It was formerly classified as the species A. ascalonicum, a name now considered a synonym of the correct name...

s for one of the three.

The preparation of Cajun/Creole dishes such as étouffée

Étouffée

Étouffée or etouffee is a dish found in both Cajun and creole cusine typically served with shellfish over rice. It is most popular in New Orleans and in the bayou country of the southernmost half of Louisiana.-Etymology:...

, gumbo

Gumbo

Gumbo is a stew or soup that originated in southern Louisiana during the 18th century. It consists primarily of a strongly-flavored stock, meat or shellfish, a thickener, and the vegetable holy trinity of celery, bell peppers, and onions...

, and jambalaya

Jambalaya

Jambalaya is a Louisiana Creole dish of Spanish and French influence. -Jambalaya varieties:Jambalaya is traditionally made in three parts, with meats and vegetables, and is completed by adding stock and rice. It is also a close cousin to the saffron colored paella found in Spanish culture...

 all start from this base.

Origin of the name

The name is an allusion to the Christian

Christianity

Christianity is a monotheistic religion based on the life and teachings of Jesus as presented in canonical gospels and other New Testament writings...

 doctrine of the Trinity

Trinity

The Christian doctrine of the Trinity defines God as three divine persons : the Father, the Son , and the Holy Spirit. The three persons are distinct yet coexist in unity, and are co-equal, co-eternal and consubstantial . Put another way, the three persons of the Trinity are of one being...

. Louisiana is a strongly Roman Catholic region.

The term is first attested in 1981 and was probably popularized by Paul Prudhomme

Paul Prudhomme

Paul Prudhomme is an American celebrity chef whose specialty is Cajun cuisine. He is also the owner of one of the top restaurants in New Orleans, K-Paul's Louisiana Kitchen.-Early life:...

.

In other cuisines

The term has occasionally been used to describe various other triples of important ingredients in a variety of cuisines.