Coconut Curry Sauce

Heat the oil in a medium saucepan or pot over medium-high heat. Add the onions and salt and cook, stirring often, until the onions soften and turn a bit translucent, about 3 minutes.

Add the garlic and chile, if you're using one, cook, stirring, until fragrant, about 1 minute.

Add the curry powder and cumin. Cook, stirring as the spices roast and sizzle until they, too, give off a heady aroma, about 1 minute.

Add the black pepper and cardamom seeds. Stir to combine everything. Add the whole peeled tomatoes with all their juices and the coconut milk. Stir to combine and bring the curry just to a boil. Reduce heat to maintain a steady simmer and cook until the flavors blend, about 15 minutes.

At this point you can store the curry sauce, covered and chilled, for up to 3 days. Or go ahead and make dinner: Add the shrimp, fish, chicken, tofu, and/or vegetables. Simmer until everything is cooked through, about 3 minutes for shrimp or fish, 5 minutes for chicken, and up to 10 minutes for some vegetables. If you're using a combination of ingredients, add the longer-cooking ones first and the shorter-cooking ones towards the end so everything gets cooked at pretty much the same time. Luckily, the longer-cooking vegetables tend to have a wider window of being tender but not mushy and can follow the lead of the shorter-cooking shrimp or shellfish that you definitely don't want to over-cook.

Stir in the basil, if you like, and serve the curry, sprinkled with green onions, if you like. It's particularly delicious alongside rice, but some flatbread is good too.