This is the second time I am writing about Haven Pizzeria Napoletana in two years. I am goofy on pizza, including Haven’s, which is a short walk from my home. I like the owner, an accountant named Tiger Mullen.

I got wind of Haven in the spring of 2012 from a friend who said, “Check out the accountant who is spending millions to open a pizza shop that is within a block of five other pizza places.”

I decided to investigate, met Mullen, wrote about his obsession and, as a pizza lover myself, I became a regular customer.

But this story is not all about cheese, tomatoes, good vino and happy times. There is some burnt crust around the edges.

Mullen, by his own admission, muffed his initial foray into the pizza business with a romantic vision that was short on execution. Mired in debt, he sold the pizza business after less than a year. The new owners, who were former clients of his accounting practice and initial investors in the restaurant, ran it for a year. Then Mullen bought it back, and as of April 1, is once again a majority owner of the restaurant.

Got all that?

“There is really a good business angle to this,” said Mullen, who is a successful accountant and hails from a family with a business background. “I really thought I could execute my vision through my management team, sitting in my remote [accounting] office at my desk.

“What I learned was that unless I was in the dirt with sleeves rolled up, involved in every aspect, I could not create what I had envisioned.”

Mullen’s candor is refreshing.

His dream is to create an all-star, artisanal Italian pizzeria in downtown Bethesda, where there is plenty of competition for pies. It was spurred by his days as a kid, summering with his grandparents in Connecticut. They would take him to New Haven, where he developed a love for pizza at Frank Pepe Pizzeria Napoletana. Mullen also wanted to replicate other pizza meccas, such as Pizzeria Bianco in Phoenix (one of my favorites).

He put some thought into the product; Mullen interviewed 63 pizza chefs before he found a guy he liked. He shelled out $400,000 for two custom-made, 12-by-12 foot coal-fired Italian bread ovens that weighed so much he had to buttress the floor with steel beams.

He sampled pizza shops around the country.He almost burned his house down refining his own recipe.

But even the best products demand exact execution in the delivery.

From the minute Mullen opened Haven on Feb. 15, 2012, he and his partners were in the hole. It took 18 months to get the required permits from Montgomery County building inspectors.

“During that time, I was paying full rent, insurance, utilities,” Mullen said. “I had a manager and an assistant manager on the payrolls. We were way over budget.”

Service at Haven was poor. Orders got lost or delayed. You could sit at the bar and not get noticed. He said he should have done more of the hiring himself, instead of delegating. The cost-controls on the bar, the kitchen and supplies were too loose, making it difficult to get a precise picture of the finances, Mullen said.

The ovens were a problem. One would have been enough; the second oven went virtually unused. Even with one, spacious oven, orders were bungled for lack of coordination, mostly because of the different baking times required for different size pizzas.

Even with those mistakes, Mullen said the pizzeria made money on an operating basis. It was packed nearly every weekend, starting Thursday night. I know, I waited in line for a table.

“It was profitable,” Mullen said. “We had a loss for tax purposes, but that was depreciation.”

Even with the operating profits, the debt from the construction weighed heavily. By the fall of 2012, he had to ask the partners for more money to cover the debt — known as a cash call.

Two of Mullen’s partners wanted to use the cash call to buy a majority share of the restaurant. Mullen reduced his interest in the business to 20 percent, surrendering control.

“I didn’t want to be there and manage it and put in my blood, sweat and tears” without ownership control, Mullen said.

The new partners took over Jan. 1. 2013, less than a year after the pizzeria started.

The new owners went to work. The giant booths that Mullen had installed were reduced in size, creating more flexibility. A new manager, who had worked at a big restaurant chain, instilled business practices that kept a closer eye on inventories, particularly the all-important bar, where the big margins are made.

“That really tightened up controls and provided more accurate financial reporting,” Mullen acknowledged.

They put a frozen cheesecake on the menu, which made Mullen blanch but sold like crazy. They added new sandwiches.

As he watched the new owners take over, Mullen — with a 20 percent stake in the restaurant — pined to get back in control. So he sold his boutique accounting practice last year and bought out the two partners.

“I knew I could not implement my vision remaining behind the desk,” he said.

Now he owns a majority of the restaurant with some other investors. The old partners are out.

This time around, Mullen is determined to implement his vision for an artisan pizzeria, serving ingredients such as imported San Marzano tomatoes, hand-pulled mozzarella cheese and fresh New England clams.

He is making everything from scratch in-house, from daily gelato to organic flours to fermenting dough for 48 hours to deepen the flavor. There is one-size pizza, an 11-inch Neapolitan, compared with the 10- and 16-inch choices. One-size pizza also contributed to revenue because everyone orders his or her own pie.

Mullen has fired up the second oven for appetizers and breads. The rustic breads will be sold by the loaf and used in lunch sandwiches. They will also anchor a new breakfast menu including freshly squeezed juices, special pour-over coffee, and stations where customers can toast the bread and top it with imported cheeses, fruit preserves or basics like butter and cinnamon.

He even changed the wait staff uniforms and is renaming the business Pitzze Table.

Mullen has learned the concept of asset utilization, which means the restaurant — especially those ovens — needs to be serving all day long to bring in the cash. He even bought a couple of old trucks to rev up a catering operation, which will be known as Tomato Flyer Pizza Co.

One other thing: He is there nearly every day.