A Mexican chef preserves tradition, and remembers her mother, by making this one dish

Angela Atenco Lopez with her son Luis in the kitchen at Angela's Cafe in East Boston.John Blanding/Globe staff

In her tiny restaurant kitchen in East Boston, a long way and many years from home, Angela Atenco Lopez lays out ingredients and begins to work. She places dried red chiles in a pan over a low flame and slowly turns them with her hands, leaning close to judge the aroma and hue as the chiles transform from almost black to the color of a deep, angry bruise and then to mahogany.

Debes cocinar lentamente , she says. You must work slowly.

Her mother, Dolores, taught her that. An old faded portrait of her hangs on a wall nearby. Angela thinks about her as she cooks, as Mother’s Day approaches and always.

Many years ago, in the Mexican village of Metepec, Atlixco — in the state of Puebla, in view of the snow-capped volcano Popocatepetl and Paso de Cortes, where the conquistadores descended into the Valley of Mexico four centuries earlier — Dolores taught her to make the dish she is cooking now at Angela’s Cafe.

Angela was not much more than 8 and allowed at first only to watch while aunts and cousins helped. The work was slow, and Dolores was fastidious and strict. There was one way to do it. No other.

The dish required eight days of painstaking work and a score of ingredients — almonds, sesame seeds, raisins, cloves, plantains, pasilla chiles, ancho chiles, mulato chiles. . . . Each had to be prepared with exactitude, toasted on a comal or fried in fat or charred over a flame to achieve a certain color or smell. Then everything was ground together on a metate — stone scraped against stone until the mash was a thick, silken paste. Then Dolores fried the paste in lard and thinned it with broth. A turkey was killed and plucked and lowered into the sauce in a massive clay cazuela, where it was left to simmer very slowly over the barest of flames.

It should never be hurried, her mother told her. Time was what made it special.

When the sauce was finally done, it was a deep, tarry brown, with a mirror gloss that could reflect a face peering into the pot. A stolen taste from a spoon was a bloom of unfolding flavors, growing and fading like passing thoughts — fruit and earth, a prick of bitter char, sweetness, a slight sting of heat.

Family, friends, and other villagers soon arrived at their door. For whatever occasion it happened to be, a wedding or holiday, most other households in the village would have made their own pots of sauce and turkey, too. But in the height of celebration, as villagers passed from house to house, crowds came and lingered — a hundred people or more in the course of a day — because the food they found there was the best.

The dish, of course, was mole poblano, the celebrated food of Mexico and a regional pride of the state of Puebla, where it is said to have been invented by 16th-century nuns at the Convent of Santa Rosa. Mothers all over the country taught their daughters to make it, as Dolores taught hers.

Mole, perhaps more than any other dish in Mexico, encapsulates the nation’s cultural identity. The legend of its creation has many variations. In one, it’s not nuns who first make it but a monk. In another, an angel helps inspire the recipe; elsewhere it’s told that a gust of wind blows a profusion of things into simmering pots of turkey. The true origins of a dish so ubiquitous are frustratingly elusive. Scholars can find no printed recipes from before the 19th century. Some handwritten ones predating that have been unearthed, but then the trail goes cold.

In the vacuum, a debate with deep and bitter divides has raged. Food historians and anthropologists from time to time have tried to settle it, with no clear success. Some say the dish is incontrovertibly a Spanish invention, largely because everything but chiles and the essential (some say defining) ingredient of chocolate was brought from the Old World. Some also say that a dish with so many ingredients would more likely have come from the Baroque Spaniards, who tended to empty the spice cabinet, than from the Aztecs, who preferred simplicity. The nail in the coffin, these scholars say, is chocolate, which was purely ceremonial to the Aztecs. They would have been horrified by its use in food.

But it’s clearly not as simple as that. A staple of Aztec cuisine — as documented in an exhaustive catalog of Aztec culture by a 16th-century Spanish friar, Fray Bernardino de Sahagun — was sauces made from chiles and other ingredients like fruit and maize ground together on a metate. For centuries before the Spanish arrived, the Aztecs had cooked turkeys in these sauces.

As for chocolate, the Aztecs commonly flavored their ceremonial chocolate drinks with ground chiles, a fact that leads some to speculate that the Spanish very well might have received the idea for this flavor combination in the form of an offering from the Aztecs, who originally mistook the conquistadores for gods.

Whatever the truth, it is hard to imagine that mole came to be in any way but through the slow, inevitable mingling of cultures, with ideas and ingredients and techniques exchanged and borrowed and substituted again and again until it became something new and of its own. Even Angela, who says she adheres religiously to her mother’s exacting recipe, has tweaked a thing or two in the last 60 years, to adapt to local tastes or because certain ingredients are harder to get. What remains constant is the feeling behind it.

“The secret,” she says, “is to be happy when you make it. To be full of love.”

Angela is 73 now, with the same inquisitive dark eyes as her mother’s in the portrait on the wall. She’s been through a lot in the course of that time. Angela says she came to this country in 1993, as so many do, for a better life. She has found that. Her two sons, Luis and Joel, help her run her two Angela’s Cafe restaurants, both in East Boston.

But there is a price. She misses home. She misses the big extended family that remains in Mexico. She often thinks about visiting, but between the restaurants, there is never time. Next year, she keeps telling herself. And, in any case, her mother, her companion and inspiration, passed away long ago.

Angela has blenders and other equipment that make preparing mole easier now, but she still does it over the course of days, like her mother taught her. She fell in love with cooking, she says, because she learned it from her mother. So while she makes her mole now, slowly toasting the chiles and stirring the sesame seeds in a pan just until they are golden, she pretends she is in Mexico and that her mother once again is beside her.