PORTLAND, Maine — In 2009, Portland was pizza impoverished.

Mike Keon walked up and down Congress Street looking for a decent slice and came up short.

Seizing the opportunity, the fisherman and chef formed a partnership with Anthony Allen, the best pie maker he knew, to open OTTO Pizza.

“We started very barebones with all used equipment,” said Keon, who leased a 300-square foot space at the corner of Congress and Forest streets for their first slice shop. “It was very minimal.”

Four years later OTTO Pizza has 215 employees working in five thriving shops in Portland and Boston. Two more stores will open by summer’s end in South Portland and Lynnfield, Mass., and in the next few weeks OTTO will hire 50 more people.

From a tiny slice shop opening in the depths of the recession on a street pocked by empty storefronts, to a marquee tenant in a high-end shopping complex opening north of Boston in August, OTTO is building a pizza empire slice by slice.

To sustain such growth, the founders keep their eye on the pie.

They treat pizza as more than a commodity. Each pie requires careful attention.

“You have to understand pizza, and dough. If you mishandle the dough, it’s a completely different product,” said Allen. “It may look fairly simple, but there’s a lot of history that goes into it.”

Allen’s history with pizza goes back to Rome.

As a teenager he fell in love with pizza while backpacking through Europe. The Nantucket native returned home and opened Anthony’s Pizza in 1981, giving islanders a taste of authentic Italian za.

He has never lost his focus on the perfect pie.

“We spend a lot of time and energy to make sure it’s consistently done the right way in all the shops,” said Allen, 51.

With flavors such as mashed potato, bacon and scallion; and mushroom and cauliflower OTTO’s imaginative pies appeal to college students, tourists and harried office workers — or anyone with a curious palate.

“I like to do things that are a little more interesting,” said Keon, whose unusual combinations came about as an experiment.

While cooking a meal with fresh herbs and vegetables culled from the Portland Farmers Market at OTTO one night, “I said “let’s toss it on the pizza,’” he said.

Mushroom and cauliflower pizza was born. “And it was delicious.”

Besides knowing how to craft a great pie, the owners have another strength, knowing when to take risks. The first shop they opened outside of Maine, at Harvard Square in Cambridge, Mass., in 2011, seemed like a natural next step.

But not all businesses that expand outside the state find success so quickly.

“Everyone else tried to scare us away saying ‘you’ve done well in Portland, slow down,’” recalled Allen.

“We knew in our heart without doing the demographic and foot traffic studies, we’d sell a lot of pizza there and it would make sense,” said Keon.

And it has. Located across from Harvard University, it’s one of their busiest shops.

That creative spirit and ability to think outside the pizza box caught the eye of national retail development firm WS Development.

The company’s newest lifestyle center MarketStreet, which opens in Lynnfield, Mass., in August, was looking to add some local flavor to their offerings.

“We looked at a laundry list” of pizza places said Todd Norley, a leasing representative for the center, anchored by Whole Foods, Pottery Barn and 250 apartments.

OTTO rose to the top quickly.

“The pizza is second to none in the Boston area; I’d be hard pressed to find a better slice,” he said.

Besides the butternut squash, ricotta and cranberry pie, Norley selected OTTO for something more intrinsic: the company’s origin.

“Portland, Maine really embodies that independent entrepreneurial spirit and that’s something that MarketStreet is trying to replicate,” he said.

The power of Portland’s food culture, which rivals cities 10 times larger, such as San Francisco, resonates nationwide, he said. “It gives what we do an identity; they are crucial to the brand,” said Norely.

Keon and Allen recognized that straight away.

By building Portland into their logo they added a place identity that’s only strengthened since they opened.

“Portland is the identity,” said Allen, who uses Portland, Maine on his logo, boxes, and signage no matter where a new OTTO surfaces.

That branding has been so successful, that Norley considers OTTO in line with iconic American brands.

“OTTO in a much different, smaller way embodies the same characteristics as Whole Foods, LuluLemon and even Apple,” said Norley.

Keeping such lofty company could go to your heads, but the men stay grounded.

“We appreciate every slice we sell, we really do,” said Allen.

And so do town officials in South Portland, excited that the Portland pie is crossing the Casco Bay Bridge soon. OTTO opens at the corner of Cottage Road and Highland Avenue in September.

“I’ve gotten addicted to the butternut squash pizza,” said South Portland City Councilor Linda Cohen. “I’ve heard some people say they could just eat their crusts and be happy.”

OTTO, which is Italian for eight, reflects the number of slices in a pie and could also be their next store. The men are in preliminary discussion to open an OTTO along Boston’s growing Seaport District in the next few years.

“Things come at us all the time,” said Allen. “We pass on a lot more stuff than we take on. We have some discipline. But … who knows?”

Kathleen Pierce

A lifelong journalist with a deep curiosity for what's next. Interested in food, culture, trends and the thrill of a good scoop. BDN features reporter based in Portland since 2013.