Well past midnight, as oldies blare from a satellite radio in an upstart Adams Morgan eatery, the believers and converts -- a guy with tattooed arms, a woman with a nose ring, a guy with a "Free Michael Jackson" T-shirt -- come trickling in.

"I'd rather go here than anywhere else," Dan Bailey, 28, said as he lined up for a falafel sandwich, a Middle Eastern snack of fried ground-chickpea patties stuffed into pita bread.

In a neighborhood famous among late-night partiers as the land of jumbo-slice pizza, the falafel sandwich is offering another way to refuel after hours of club-hopping.

Since it opened last fall in the 2400 block of 18th Street NW, the Amsterdam Falafelshop has flourished. On any given night, hundreds of people climb a half-flight of brick steps into the sliver of a storefront, with its hardwood floors, multihued walls, Amsterdam motif (some signs are in Dutch) and eight tables -- four inside and four on the patio.

"People come in and say, 'Thank you so much for opening. Thank you for not having us eat pizza,' " said Arianne Bennett, 36, a Web page designer who grew up in the District and opened the shop with her husband, Scott Bennett, 54. "It's the strangest thing."

As befits the bar- and club-intensive neighborhood, the doors stay open late: until 2:30 a.m. Tuesdays and Wednesdays and 4 a.m. Fridays and Saturdays, about the same hours as the three jumbo-slice shops that are steps away. And the Bennetts often are ready to pitch in at a moment's notice: They live upstairs.

The menu is minimalist: falafel sandwiches, French fries (deep-fried twice, in the European style), soft drinks and "virgin" brownies, a joking reference to Amsterdam coffee shops that sell marijuana-laced brownies. That's all, except for the occasional chicken schwarma special and the free toppings bar, where customers can add grilled eggplant, hummus, cabbage and more to their sandwiches.

The ponytailed Bennett, who is part Native American, said he often longed for an alternative to the late-night offerings in Adams Morgan, where he was a bartender for two decades.

After vacationing in Amsterdam many times and frequenting the falafel shops popularized by immigrants there, Bennett had an idea: This could work in Adams Morgan.

He hired chef Walid Abuelhawa, 52, a Palestinian immigrant and longtime local chef who had worked as a child at his father's falafel shop in Jerusalem.

Five days a week, Abuelhawa is in the compact kitchen, chopping, mixing and grilling as he whips up his father's old falafel recipe and prepares the toppings.

"I'm surprised the success we are seeing. I'm really surprised," he said proudly.

Raed Alkhatib, a Palestinian immigrant who was raised in Jordan and sells roses in Adams Morgan, called the restaurant's falafel "as good as back home. This is the best."

The place is unquestionably and unapologetically quirky. No paper plates. No forks. Sandwiches are served on sandwich wrapping paper.

"I try to keep the trash down," said Bennett, noting that paper plates from the slice shops litter the streets nightly. "If you see Adams Morgan on Sunday morning, it looks like Chernobyl."

Environmental concerns aside, Bennett said, he also pitched the plates because some customers used them to devour the toppings as if they were part of an all-you-can-eat salad bar.

After a while, the forks vanished, too. Some customers, he said, piled on excess toppings, knowing that the towering delicacy could be tamed with a fork.

But the preventive measures haven't fazed regulars such as Catherine McAran, 24. One recent night, she piled toppings well above the rim of the pita, as if she were building a mini Mount St. Helens.

"Cathy gets her aerobic exercise when she builds her falafel," night manager Mike Dugan, 55, noted dryly.

Moments later, McAran produced a plastic fork lifted from a pizza slice shop on the way over.

"I do it all the time," she said. "I came in the week they opened. I have to eat it once a week. I'm addicted."

The pizza proprietors and their partisans aren't worried by the new competition.

"It hasn't affected us at all. My business is going up every day," said Jawed Khan, owner of Jumbo Slice Pizza on 18th Street NW. Khan, who has lived in Kuwait, has eaten at the falafel shop and said he's had better.

Shah Chishti, owner of Pizza Mart, which bills itself as the District's original home of the jumbo slice, has been there, too. Chishti said he liked what he tasted.

"They're a very good place," said Chishti, who also hails from Pakistan and grew up eating something similar to falafel. "They have good food."

Still, most ravenous revelers seem to go for the jumbo slice.

"It's quick, easy and delicious," said Mike Seium, among the customers striding out of Pizza Mart one recent night cradling mozzarella-laden wedges that measured 16 inches long and 11 inches wide.

Nan Hee, 33, said the jumbo slice is simply a matter of tradition.

"It's not the best [pizza], but it's an institution," she said. "You go to Adams Morgan to the bar, you get a huge slice."

Bennett said he's grateful to the slice shops for starting the "nocturnal feeding frenzy."

But with that frenzy has come inebriated customers.

"We get our share of drunks," he said. But "frankly, people who come for falafel are usually a different kind of drunk than the pizza drunks. There's no fights here."

James Norton, an accountant who resides in the neighborhood, said that despite the occasional "drunk idiots," the falafel shop is looking like a keeper in a late-night landscape known for more familiar flavors.

"I think generally in D.C., people don't know what falafel is," said Norton, who worked briefly at the eatery as a security guard. "I didn't think they were going to make it. Who eats falafel?"

In Adams Morgan, Amsterdam Falafelshop offers an alternative to jumbo-slice pizza joints.Dana Lewis and David Lewis eat falafel at the Amsterdam Falafelshop after bar-hopping. The shop offers only a few items, but it stays open late -- until 4 a.m. Fridays and Saturdays, about the same as the jumbo-slice places.