Chef Judy Klumick is succinct when describing Black Sheep Luncheonette, an Edgartown eatery she runs with Patti Canha.

“The Luncheonette is food truck style,” she said. “Wham, bam, done.”

Patti Canha is the hostess with the mostess. — Jeanna Shepard

Although those words don’t begin to describe the cozy atmosphere she and Ms. Canha have created, it does accurately describe how fast the food goes out the door. Earlier this week, the crab rangoon cracklebread pizzas sold out in an hour and a half. Cracklebread pizzas, a stiff cracker topped with a spread and salad, were on the menu when Black Sheep operated as a wine bar at night. When the Luncheonette began, Ms. Klumick added her own spin to the dish.

“I really ramped it up and started doing Greek salads on top, farm salads on top, Caesars,” she said. “It’s basically a blank canvas.”

During the summer season Black Sheep is an upscale market and catering business. But beginning four years ago, after closing down around Columbus Day it is reborn solely as a lunch place. Ms. Klumick and Ms. Canha run the store like a well oiled machine (oiled with specialty extra virgin olive oil of course), and both are essential to its success.

Owner Mark Venette gets out of the way when it's luncheonette season. — Jeanna Shepard

“If one of us can’t show up, it doesn’t happen, the door closes,” said Ms. Canha. “If one of us is sick, there is no other person. It can’t happen without the two of us.”

Typically, Ms. Klumick does the work behind the counter, creating and executing menus, while Ms. Canha is the queen of customer service and the bookkeeper. But as with any two-person operation, their roles overlap.

The idea for the Luncheonette came about the same year Ms. Klumick started working at Black Sheep. She and Ms. Canha brought the proposal to owner Mark Venette. Mr. Venette eagerly started telling people about the idea the next day. Though both women had been on the Island for years, the two hadn’t met until they started working together at Black Sheep.

“[The connection] was pretty instant when we started here, she’s a very kind, caring, mother-type,” Ms. Klumick said of Ms. Canha. “I wouldn’t have done it if it hadn’t been such a good working relationship. It’s got to work, these are tight quarters. And she knows, she can read me.”

Luncheonette is open through Christmas and then back again in March. — Jeanna Shepard

New menu items are always on Ms. Klumick’s mind, when she’s cooking, cleaning, even in her dreams. She keeps a handwritten list of ideas handy.

“People want to know they are not just going out and just getting lunch,” said Ms. Klumick. “They are getting something I’ve thought about and crafted for them. Because you can go anywhere and get lunch, and you go, yeah, this is pretty good. But here it’s pretty darn good, right Patti?”

Ms. Canha agreed, saying she just ran into a bank teller who told her she was so glad to have worked in the Edgartown branch that day because she’d been craving a noodle bowl. Although everyone knows Wednesday means noodle bowls, they don’t know exactly what will be in the noodle bowl.

“I don’t like redundancy,” said Ms. Klumick.

And every menu item has Ms. Klumick’s little twist.

“It’s not just a ham sandwich,” she said.

The trio behind the noodle bowls and cracklebreads. — Jeanna Shepard

“It’s not just a ham sandwich,” Ms. Canha echoed.

Ms. Klumick turns to local produce for inspiration. She is intent on making the most of the squash season, roasting pumpkin for soup and butternut squash for paninis while loading up soups with Island vegetables. The kitchen is small but Ms. Klumick doesn’t seem to mind, making the most out of induction burners, a convection oven, a grill and a smoker. It’s the same kitchen she uses all summer to cater to hundreds.

“You don’t need a giant six-top gas grill and a big hood to cook good food,” she said. “You just have be patient.”

The Black Sheep Luncheonette runs through Christmas in Edgartown and resumes at the end of March to just before Memorial day. Hours are from 11 a.m. to 3 p.m. It is located at 18 North Summer street in Edgartown.