Where you’ll find Jeff Tunks: On the line at District Commons. (Bonnie S. Benwick/The Washington Post)

This week, as Jeff Tunks ramps up the kitchens of side-by-side restaurants with very different concepts, the executive chef is 6-feet-3 inches of anxiety.

“Nervous? That’s an understatement,” he says. “It scares the bejeezus out of me.

“Let’s face it: I’m a control freak. Everything can be in order, but if we have a Bobby Flay Situation — you know, people waiting in line for an hour — it’ll kill me.

“It’s not a religious experience. It’s a burger.”

Tunks and his Passion Food partners Gus DiMillo and David Wizenberg have done their part. With cooperation from Verizon and Micros and the gods of the hospitality, they will open at least the Burger Tap & Shake half of their new space in Foggy Bottom by midweek. (The other half: District Commons, which hosted a warmup party Sunday night.) Tunks has handed over the reins of DC Coast to Matt Kuhn.

Some of the customers who have been peeking in BTS for weeks were lucky enough to be invited inside the past few days for free burgers, fries, onion rings and shakes.

Tunks has been executive-cheffing since 1985, but BTS is his first foray into counter service. In addition, he’ll be parked on a highly visible line in District Commons: “People have been waving to me through the windows while I’m working,” he says. I’m right out there.”

In a private, behind-the-scenes preview for All We Can Eat on Sunday, Tunks showed off lots of good ideas and cool kitchen toys. His years of experience and months of research and field trips were evident.

In the back kitchen that serves both restaurants:

The burger press will see plenty of action. Daily. (Bonnie S. Benwick)

* The kitchen floor is a seamless, gun-metal-gray rubber surface. It feels slightly springy underfoot and eliminates the need for thick mats.

* The L-shaped walk-in has enough room to hold rows and rows of the vegetables and fruits Tunks has pickled for both restaurants, in addition to the usual stuff that needs refrigeration.

Chocolate ice cream , as it comes out of the whiz-bang Emery Thompson batch freezer. BTS milkshakes will incorporate house-made ice cream. (Bonnie S. Benwick/The Washington Post)

* The 12-quart Emery Thompson batch freezer can crank out ice cream in 11 minutes; again, Tunks’s penchant for control directed him to this high-priced model, which has the capacity to control the consistency of the product whether it’s sorbet, gelato or something in-between. The chef’s eyebrows raised as he describes the amount of butterfat in the ice cream they’re using for milkshakes: 14 percent. Hooboy.

* The smoker set atop a stack of combi ovens (convection and steam) will be used to cold-smoke onions and short ribs.

And in front, on the District Commons side:

* There’s a gleaming open hearth for flatbreads and pretzel bread.

The Berkel meat slicer: A thing of beauty. (Bonnie S. Benwick/The Washington Post)

* Tunks installed an old-fashioned farm dinner bell on the wall above the Berkel, which he’ll ring to signify staff meal and various specials.

* The line where the chef will spend most of his time, has fryers whose oil (“creamy, soy, transfat-free” ) lines connect to tall, 800-pound tanks in the back kitchen.The fryers can be filled and emptied with the touch of a button. (“Just like McDonald’s!” Tunks says — the only time I’d suspect he’d employ such a boast.)

On the BTS side, the line’s built for speed. The operation’s in full view as well:

A blueberry-pomegranate shake, with 20 beers on tap and BTS/DC bar manager Kevin Soloninka in the background. (Bonnie S. Benwick/The Washington Post)

*The beverage-dispenser island behind the counter allows for easy staff access. It has 20 beers on tap and a row of milkshake machines at the ready. Nonalcoholic shake flavors: chocolate, vanilla, strawberry, BTS Shake, black and white (choc and van), espresso-caramel, cherry-vanilla and blueberry-pomegranate.

During Sunday’s test run, Tunks was all smiles for out-of-town family even as he fretted over what needed fixing: “See the signs overhead? They’ll be changed the next time you come in. We need to streamline the choices.”

See that sign above the BTS counter? It’s on the chef’s list of Things to Improve before opening day. (Bonnie S. Benwick/The Washington Post)

Also on his list: the Micros ordering system. “Orders that had ‘no cheese’ on them weren’t coming out that way,” the chef reported. “To-go orders weren’t reflected on the tickets,” with the potential to cause a domino effect that would muck up the fledgling operation. There was no systems support available over the weekend, but it was a high-priority item that Tunks intended to correct today. Orders that were coming off a relatively short customer line on Sunday took about 11 minutes, on average.

“I call this part ‘passing a stone,” Tunks deadpanned yesterday. “We’re waiting on Verizon to hook up phone and Internet. We can’t call in sales without it.”

On top of it all, Tunks, newly 50 and still sporting the sleeker physique he achieved in 2004, hasn’t gotten to exercise much lately.

“Between sampling the milkshakes and burgers for this last week of training, I need to see if the building has a fitness center,” he says.

District Commons/Burger Tap & Shake, 2200 Pennsylvania Ave. NW. BTS: 202-587-6258.