WHEN HE first immigrated to the U.S. from the Ivory Coast 19 years ago, Morou Outtara used a delicate hand when working the flavors of his homeland into the menus of the restaurants where he cooked.

Americans, he suspected, weren't quite ready for the bold West African flavors such as aromatic alligator peppers or creamy palm-nut sauces that were common in his mother's home.

But as he saw diners grow more comfortable with assertive Asian and Indian seasonings, Outtara decided it was time to let African flavors play a more dominant role in his menus, rather than merely accent them.

So 18 months ago, he opened his upscale Farrah Olivia restaurant in Alexandria, Va., where comfortable dishes such as rib-eyes are rubbed with ground coffee and a pungent and spicy West African peppercorn called grains of paradise, and where beignets are stuffed with a mash of black-eyed peas.

"We explored the Asian rim thing and the Indian has been here forever," he said of the evolving American palate. "For six, seven years now people are playing with the idea of African food, and people are now starting to accept it."

Once limited mostly to immigrant enclaves, the robust flavors of African cuisines recently have begun following the trajectories of Italian, Latin, Asian and Middle Eastern foods - themselves once foreign flavors here. "It's one of the last frontiers," said Kemp Minifie, executive food editor at Gourmet magazine. "As there is more awareness and more learning about Africa and that it isn't just one cuisine, there will be more restaurants doing it."

Americans' relentless appetite for newer, bolder flavors paired with foreign travel and awareness of global issues (even if only via high-profile celebrity adoptions), have made for easy passage of African flavors into new markets.

Until recently, for example, the editors at Food & Wine magazine felt it necessary to suggest substitutes whenever a recipe called for harissa, a spicy sauce from Tunisia. Today it is common enough to stand on its own.

"With the Madonnas and Angelina Jolies of the world, people who did not know where Namibia is do now," said Tina Ujlaki, executive food editor at Food & Wine.

The cuisines of several African nations in particular seem to be benefiting. Moroccan, Tunisian, Algerian and Egyptian foods are especially poised to gain wider appeal, according to a recent survey by consumer research firm Packaged Facts.

In Washington, D.C., Minneapolis, New York and Chicago, the trend is helped by large immigrant communities of Ethiopians and Somalians, said food consultant Elaine Tecklenburg, who wrote the report.

There also has been an influx of African refugees, many of them settling in rural areas and creating a demand for foods from home. Census figures show that more than a million African-born refugees and immigrants were living in the U.S. in 2002, more than double the number from a decade earlier.

It also helps that Americans are finding the flavor profile of many African cuisines - hot, spicy and sweet - approachable, in part because it's a trio found in other already popular cuisines, such as Hispanic. And though they may not be conscious of it, many people already are familiar with tastes found in African cuisines.

Many foods and flavors of the American South can be traced to Africa via slaves, said food historian Jessica B. Harris, who has studied African influences on American cuisine. "If you have had collard greens, you can understand callaloo," a leafy green vegetable of West Africa.

It also helps that many of the seasonings found in African cuisines have roots elsewhere. Indian and Malaysian spices are prevalent in southern Africa, while northern countries have more Middle Eastern influences.

Flavors and foods left in Africa from European settlers, including the French, Portuguese and Italians, also help make African cuisines more accessible. And even many American foods have African roots.

And so while not yet household names here, spice blends such as harissa, Ethiopia's garlicky berbere and Morocco's complex ras el hanout (recently featured on Bravo's "Top Chef") are showing up on menus, spice and gourmet catalogs, and cookbooks.

"Morocco and Tunisia seem very familiar now," said Ujlaki. "I am sure there will be a packaged dukka [an Egyptian blend of seeds and spices] in the supermarkets in the next couple of years. I think some of the spice companies are now hip to it."

Ethiopian-born celebrity chef Marcus Samuelsson (who had a brief stint in Philadelphia at Stephen Starr's now-defunct Washington Square restaurant) can take credit for some of that. His most recent book, the James Beard Foundation award-winning "The Soul of a New Cuisine," is a culinary tour of African flavors.

That success prompted him to launch Afrikya, a brand of African spices targeted to chefs and adventurous home cooks.

But he's hardly alone. Nirmala Narine, of Nirmala's Kitchen, an exotic gourmet importer in New York, sells a line of five African spices at natural-foods stores nationwide, and Vann's Spices in Baltimore has introduced a similar line.

Meanwhile, spice giant McCormick & Co. recently called the common North African and Middle Eastern spice combination of poppy seeds and rose one of the top 10 flavor pairings for 2008.

"It's been gradually happening," said Samuelsson, who in February opened a pan-African restaurant in New York called Merkato (named after the large open-air market in the Ethiopian capital of Addis Ababa). "North African and Arab spices are the best known to American cooks, but you are now seeing those spices like harissa, za'atar and dukka showing up on menus." *