Three Sisters

A curated weekly email

One recipe a week, from the diet linked to longer, healthier lives.

Corn, beans and squash are planted in the same mound because they solve each other's problems — and they complete each other on the plate. Corn runs short on lysine, beans on methionine; together they cover all nine essential amino acids, a complete plant-based protein. Each issue is one dish built on all three.

the pole the nitrogen the mulch

The planting

It started as an agricultural idea, not a diet.

Long before anyone counted a nutrient, farmers across the Americas worked out that these three plants solve each other's problems when you put them in the same mound. The Haudenosaunee named them the Three Sisters. Versions of the same polyculture run from the Great Lakes down through Mesoamerica and into Central America.

Grows tall

Corn

Goes in first and grows into a living trellis. By the time the beans need something to climb, the stalk is ready to carry them.

Feeds the soil

Beans

Climb the stalk instead of sprawling, and fix nitrogen at the roots through bacteria in their nodules — replacing some of what the corn takes out.

Holds the ground

Squash

Runs along the soil with broad leaves that shade out weeds and slow evaporation. The bristly vines discourage a few pests on the way.

Nicoya, Costa Rica

A peninsula where that combination never stopped being dinner.

Nicoya is a dry, hilly stretch of Guanacaste province on Costa Rica's Pacific coast — Chorotega land, and one of five places Dan Buettner and National Geographic named "Blue Zones" in the mid-2000s.

Set the population claims aside and what's left is the cooking, which is the part worth borrowing. The traditional Nicoyan plate is corn, beans and squash, day in and day out, with rice, tropical fruit, eggs and comparatively little meat. The corn is nixtamalized — soaked and cooked in lime before grinding — which is the step that turns maize from a starch into something closer to a complete staple.

  • CornNixtamalized into tortillas at nearly every meal, plus fresh maize in season.
  • BeansBlack beans daily, often cooked down and eaten with rice at breakfast.
  • SquashAyote and chiverre, stewed, sweetened, or simmered into the bean pot.
  • Around itPapaya, plantain, eggs, hard mineral-rich well water, small amounts of meat.

What this letter claims, and what it doesn't

Nicoya is often described as a longevity hotspot. Demographers disagree about those population numbers, so nothing here rests on them — we're not going to tell you a recipe adds years to your life.

The food stands on its own. Eating patterns built on whole grains, legumes and vegetables are among the best-supported in nutrition research, and corn and beans together supply amino acids that neither covers well alone. That's the part this letter is about: cook it because it's good, it's cheap, and it works.

The letter

One recipe, once a week.

Every issue is a single dish built on all three crops, written to be cooked on a weeknight rather than admired.

The recipe

Full ingredients and method, with prep and cook times up front so you know what you're committing to before you start reading.

The three sisters in it

A short note on what each crop is doing in that particular dish — which is usually the difference between following a recipe and understanding it.

A cook's note

The substitution, the make-ahead, or the one step worth not rushing. Written after actually cooking the thing.