David Chang's back was killing him. The chef, founder and worrier in chief of the Momofuku empire could barely find a comfortable position on a backless wooden stool inside his latest restaurant, a soaring, two-level operation at CityCenterDC, his first in Washington. He herniated a disc a few years ago, but he blamed his current pain on pure stress.

"It's not a surprise," said the Northern Virginia native, "Every restaurant opening, my back gives out. It's just from the pressure and nerves."

Chang would prefer to deal with the throb in his back through physical therapy, but there was no time on a Thursday afternoon last week. He was still worrying over dishes, kitchen execution, public expectations, final menus and every other detail that would likely escape the attention of the average diner. So, painkillers it was for the multiple James Beard Award winner.

"This is the week where I'm hoping they work," he said about the drugs.

If you want to know why Chang's brand new concept, Momofuku CCDC, is only now opening for Saturday dinner, more than a day behind the launch of sister bakery, Milk Bar, you can point a finger straight at the man with the bad back. Until today, Chang had not even settled on a menu or approach for the CityCenterDC space. Would it be another iteration of the Momofuku Noodle Bar with ramen, pork buns and snacks? Would it be more open-ended and creative like the Ssam Bar? Would it include a seasonal tasting menu like the intimate Ko?

Or would the D.C. location be a greatest hits collection, pulling together the best from across Chang's various restaurant concepts?

"No, definitely not greatest hits," the chef said on Thursday, still days ahead of opening night. “This is actually a serious debate: Do we offer pork buns?" Chang was also debating whether he'd sell his exquisite, deeply flavored noodle soup, the bowl that has assumed the name of his very restaurant group: Momofuku ramen.

"Yesterday," Chang said about a closed service prior to opening, "we didn’t serve Momofuku ramen. We don’t want to, because there’s a lot of ramen everywhere."

Seriously, you're thinking about not serving ramen in Washington?

“Yeah,” he said.

C’mon, you're not serious.

“I’m serious," Chang shot back. "Dude, I’m dead serious.”

That'd take guts. People would complain.

“I know. I’m just telling you. It’s very well we could open up and the menu will be as is, with greatest hits," the chef said. "But it’s trying to find that balance. Man, it’s not easy. It’s not easy at all.”

You get the sense it's not easy being David Chang, period. As if living up to his reputation, Chang was fighting demons both external and internal. He dropped his usual allotment of F-bombs, sometimes for emphasis, rarely for shock and often as a kind of release, a tea kettle boiling on a hot stove.

Chang wasn't happy with some of his ingredients and suppliers in the D.C. market. He wasn't thrilled about serving the same old dishes he's served at his previous restaurants, nor was he pleased with the execution of the new dishes he's been engineering with his team. Among the possible new plates for D.C.: a take on English chef Fergus Henderson's Welsh rarebit; an interpretation of a childhood favorite, the braised fried chicken from the now-closed Wu's Garden in Vienna; and a cold beef noodle soup with white kimchi, a Korean staple of Chang's father.

"I loved Wu’s Garden," Chang said. “The braised boneless chicken [was] one of the best dishes ever. It doesn’t look that nice, but that’s a good dish that I would want to put on here. A version of that. It doesn’t make any sense: braised fried chicken, but it’s f------ uncanny how delicious it is. But most people, I think, are a little scared because it doesn’t look like your traditional thing. But that’s sort of where I’m at: I would rather serve something that is well made and doesn’t have the composition of a traditional dish."

"At the end of the day," he added, "it’s just about good eating.”

In the end, none of the three dishes made the opening-day menu, which includes both Momofuku ramen and pork buns. The menu also includes somewhat cryptic footnotes on six different dishes. (See dinner menu below.)

Christina Tosi, founder and owner of Milk Bar, predicted last week that Chang would ultimately fall back on some of his classic dishes. The angst is part of the performance art leading up to an opening.

“We try and make ourselves think that [we'll do something all new] because it’s an important part of our creative process. But at the end of the day, if you like to make food, it’s because you like to feed people and you like to make people happy," Tosi said. "As much as there’s that wanting to be punk rock about it, you also want to please. You want people to be happy and fed.”

But Chang also felt the pressure of opening his first restaurant in the D.C. region, where his parents still live and where he still returns on occasion. "I never thought that I'd ever want to come back, ever," Chang said. "I never thought I'd move back to live in D.C. I never thought that I'd get so distant and actually successful at [a career], too, and then something happens when you get older."

It doesn't help Chang's anxiety that the CityCenterDC operation is monstrous, occupying, by one report, more than 11,000 square feet. Much of the space will be invisible to the diners, who will be confined to the street level space; a massive production kitchen occupies a similar amount of real estate in the basement.

Chang originally intended his D.C. location to cover only a fraction of that space, roughly where the private dining room (or "PDR" in Chang-speak) sits in the current layout. He envisioned an intimate, 90-seat spot, not the nearly 200-seat playground he's now opening. But this being Washington, Chang figured it would be almost impossible to launch a restaurant without a separate dining space for the fat cats or, possibly, the president.

A PDR doesn't exactly fit the image of a chef better known for his punkish, apolitical personality. "Do I really want one in the ethos of what we do?" Chang said. "No. But, like, I have to make some concessions.”

The chef has selected Patrick Curran, former chef de cuisine at the Momofuku Noodle Bar in New York, to perform the same role in Washington. Chang has also hired Mark Gears, who cooked at the high-volume Le Diplomate, to help lead the Momofuku kitchen in Washington. But after those two, Chang said, his kitchen is thin on experience. More importantly, Chang added, they're still not operating as a selfless team.

Chang has a clear measure of when a kitchen is ready to go public. It has little to do with food.

"A cook is busy and, unbeknownst to him or her, drops something on the floor," Chang began his thesis, "and someone else trailing them, or walking beside them or whatever, sees it happen and cleans up the mess without telling anyone. And no one ever gets recognition for cleaning it up, and the person that drops [something] didn’t even know they dropped something. And if you have that kind of accountability and solidarity, the food is going to take care of itself."

After weeks of training and prepping for opening night, the Momofuku CCDC kitchen team must have finally found that kind of solidarity. Or something close to it.

Momofuku CCDC, 1090 I St. NW, www.momofuku.com. Hours: 5 to 11 p.m. Sunday-Thursday; and 5 p.m. to midnight Friday and Saturday. Starting Monday, a limited number of tables can be reserved via the Momofuku Web site or OpenTable.com.