Holy trinity

The holy trinity is a mix of chopped onion, celery and green bell pepper that starts many dishes from Louisiana's Cajun and Creole cooking. It is cooked in fat until soft and forms the flavor base of gumbo, jambalaya, étouffée and red beans and rice. It is the Louisiana cousin of French mirepoix, with bell pepper in place of carrot.

How to do it

1. Use roughly equal amounts of onion, celery and green bell pepper by volume, or 2 parts onion to 1 part each of the others.
2. Dice them all to the same size, about 1 cm (3/8 inch).
3. Heat oil or butter in a heavy pot over medium heat.
4. Add the vegetables with a pinch of salt and cook, stirring, for 5 to 8 minutes until soft and the onion is translucent.
5. Add garlic for the last minute if the recipe calls for it. Some cooks call garlic "the pope".

How to use it

In gumbo and étouffée, the trinity goes straight into a hot, dark roux. The cool vegetables stop the roux from cooking further and soften in it. In jambalaya, it is cooked in the fat left from browning sausage before the rice goes in.

Substitutes

• If you have no green bell pepper, a red or yellow one works, but it tastes sweeter.
• Frozen, prechopped trinity mixes are sold in Louisiana and work well in stews.

How to store it

Chopped trinity keeps in a covered container in the fridge for 2 to 3 days. It also freezes well for up to 3 months and can go straight into the pot from frozen.

Common mistakes

• Browning it hard when the recipe wants it soft.
• Cutting the pieces unevenly, so some burn and some stay raw.
• Leaving out the celery, which gives the base its earthy note.

Where it comes from

The trinity grew out of French cooking in Louisiana, where bell peppers were easier to grow than carrots. Other cuisines have their own bases, such as Spanish sofrito and Italian soffritto.