Tambra Raye Stevenson teaches about African heritage and nutritious eating as part of a six-week class at the Masjid Muhammad, an Islamic faith center. (Craig Hudson/For The Washington Post)

It’s Sunday afternoon in Northwest Washington, and Tambra Raye Stevenson is on a mission: A spiritual mission. A food mission. A health mission.

“By any greens necessary,” Stevenson says. The petite woman with an almond complexion speaks to a student and a reporter sitting at a rectangular table. They are in a makeshift dining room surrounded by books on African heritage.

During the week, Stevenson, 34, does nutrition assessment and intervention at local health centers as part of an internship and manages NativSol Kitchen, which offers nutrition education and cooking classes. But on this Sunday she is a teacher at the Masjid Muhammad, an Islamic faith center. Dressed head-to-toe in black, she educates participants — all black — on African heritage, health and nutrition.

Stevenson believes food and nutrition are intertwined with culture, and cites studies from the Journal of Human Hypertension and the Journal of Biomedical Science that support her belief: When people of African descent adopt a Westernized diet of processed “Frankenfood,” bad things, such as diabetes, cancer and hypertension, happen. For her, it’s time for a new approach to fix her community’s problems with food.

“The current policy for nutrition education is not working,” she says. “You can never go wrong when you go back to your foundation.”

She is one of 15 people heading “A Taste of African Heritage,” a series of free community cooking classes taking place in 15 areas around the country this fall. Created by the nonprofit food and nutrition education organization Oldways, these six-week classes are the precursor to a larger program on African American health that Oldways hopes to kick off during Black History Month.

“In February it will basically be a free curriculum for anyone who wants to register as an instructor,” says Sarah Dwyer, an Oldways program manager. “The health climate that I’ve seen and what’s gone on in terms of fast food in African American communities and neighborhoods and the lack of grocery stores — it just really feels like something that needs to be put on the front burner and a new creation has to be made there.”

Like Dwyer, Stevenson also feels passionate about improving the health climate of every American, but especially African Americans.

In a cozy room with an African food pyramid pinned to a white wall, Stevenson points to a table that has collard greens, kale and spinach as its center piece.

“There’s so many benefits of greens,” she says.

Because they are low in calories and high in nutrients, such as B12 and 0mega-3 fatty acids, says Stevenson, she teaches the class to make kale chips, a kale and avocado smoothie and kale-based salad.

But it’s the lessons that you can’t taste, those that can only marinate in the forefront of your mind, that make Stevenson’s classes memorable.

During Week One, she taught the class about “imperialism on our plates.”

“You have been hoodwinked, bamboozled,” she says, using words made famous by Malcolm X more than 50 years ago. Though many have been raised on, for example, white bread, because society has implicitly and explicitly taught us that white equals good, Stevenson wants us to remember one thing.

“If it’s white,” she yells, “it ain’t right,” responds Malika Abdullah, a class participant.

“If it’s brown,” says Stevenson, “it can stay around,” Abdullah says.

Raye explains that white rice is absent of some layers of grain, so that week we make jollof rice, a traditional African dish, with whole grain red and black rice.

“There’s no racial undertones here,” Stevenson says later. “We’re talking about artificially...refined products,” but foods that are naturally white, such as cauliflower, are acceptable.

Stevenson says the class will tour the African diaspora and asks every participant to say where they’re from in the United States and where they are really from in Africa. Unsure of which country your family hails? Take a guess. Or, outside of class, take the steps to trace your roots.

In Week Two, Stevenson shows the class her “certificate of ancestry.” She paid $250 for a company to examine her family lineage, which was traced to Nigeria and Niger. She believes heritage and nutrition go hand in hand. “Culture is what makes up community,” she says, as well as pride and self-esteem. And knowing where you come from, for Stevenson, helps dictate how you eat and which foods your body needs.

“You can pay the farmer now or the nutritionist now...or the grave digger later,” says Stevenson.

Another Sunday’s lesson covered eating natural food. The topic: whole grains. Stevenson tells the class how to make millet — which feeds birds in the United States but are eaten by people in Africa, Stevenson says — with carrots and ginger. They learn the difference between real couscous and the non-organic versions, the difference between Quaker oats and organic oats, and why this all matters: because strong food, like the organic oats that are harder to rip apart, build strong people.

The students furiously scribble notes and one, Melba Wood, 36, even takes photos. She plans to make copies of Stevenson’s lessons to mail to her mom in New Jersey. Cooks of all ages can still learn a thing or two from Stevenson.

“Even at 60,” says Abdullah, a mom of five and grandmother of 16, “I’m learning so much.”