Editor’s Note: The Maine Sunday Telegram is pleased to welcome James H. Schwartz as our new restaurant reviewer. Schwartz has covered food, travel and architecture for The Washington Post, Downeast, Coastal Living and Southern Living magazines for more than 30 years. Long a commuter between Portland and Washington, D.C., he retired from his job as vice president at the National Trust for Historic Preservation in 2013 and relocated to Maine. He lives in Cape Elizabeth and Brooklin.

It’s good to be wrong every now and then. You sit up and take notice, give credit where it’s due – and possibly hear your mother’s voice intoning that “you can’t judge a book by its cover.” So here’s my true confession: I was wrong about Artemisia, a low-key restaurant on Pleasant Street in downtown Portland.

The place may look ordinary from the outside, but as I discovered to my happy surprise, it’s anything but.

From the street, you might easily walk past the front door. The two-story brick building stands next to a sprawling parking deck in the shadow of the Holiday Inn. There’s no lighted sign above the entrance, no piped music flooding the sidewalk, just a set of green awnings over plate glass windows that reveal a dining room lined by plain wooden booths.

On a recent evening, only a few tables were occupied. (The restaurant is open under the same name for lunch and brunch, as well, but with a different staff, menu and chef.)

I’d been warned that service could be slow, so we were prepared for a wait. A hostess stood just inside the entrance, swiftly showed the way to a booth and sent a waiter over before we could put away the car keys. So much for slow service. She offered a warm welcome, dispensed with drink orders and distributed the single sheet of paper with the evening’s short, seasonal menu: a handful of appetizers, pasta and entrees – many with Italian roots.

After ordering, we checked out the dining room. No white tablecloths or feints toward elegance, just straightforward booths and tables, low lighting, a lazy fan whirring on the ceiling and a few parched plants on the windowsill. Preconceived notions seemed destined to remain firmly in place.

And then the octopus arrived – braised octopus crostone ($7), a mound of the tiny creatures bathed in an intensely flavorful tomato sauce and topped with a drizzle of creamy aioli, all on a thick slice of toasted bread. Octopus done wrong is an assault to the senses and a chore for the molars (imagine chewing on a rubber band until you simply give up and swallow), but the octopus at Artemisia was an eye-opening stew of complex flavor. The meat was soft and rich, having absorbed the acidity of the tomato sauce while retaining the clean taste of the sea. The basil-flecked tomato sauce was bold but not overpowering. And the aioli – a classic French garlicky homemade mayonnaise – provided a luscious finish. If you are the sort of diner who avoids octopus because of the texture (or the tentacles), Artemisia is the place to find your culinary courage, shrug off your concerns and indulge. Eight legs? You’ll wish these octopi had 10.

Other starters proved just as satisfying. Maine crab nestled in a halved avocado ($12) was accompanied by pickled ginger that elevated the crabmeat with a one-two punch of sweet and sour, plus a satisfying whiff of spice. An otherwise basic salad of Boston lettuce, tomatoes, cucumber and bacon ($10) was served with its own delicious counterpoint: finely sliced fried shallots that added sweetness and crunch and suggested a chef having some fun in the kitchen.

By now I’d just about thrown my early assumptions out those plate glass windows. The entrees cemented my about-face.

Cod, chicken, pasta – three very different main courses, but at Artemisia, all variations on the same theme: basic ingredients, flawlessly prepared and distinguished by dazzles of intense flavor. Roasted Casco Bay cod ($22) – crispy outside, moist within – sat atop a mound of corn, summer squash and sliced red and yellow peppers, a seasonal ode to summer’s end. The sugars in the corn and the peppers heightened the natural sweetness of the fish. (Slices of hearty bread from Standard Baking Co., just a few blocks away, worked nicely to mop up the juices.) Grilled chicken ($19), often a yawner, was paired with a vivid arugula pesto, which added an irresistible peppery bite to the plain breast meat. And chef Guy Frenette’s penchant for flashes of flavor was clear in the dribble of aromatic truffle oil that elevated a classic combination of pasta, lobster, peas and cream ($18).

That last dish appeared on the menu as lumachine, a shell-shaped Italian pasta named for its resemblance to little snails, our waitress explained. “It’s the kind of dish I never want to end,” one friend said as he mournfully scraped the last bit of lobster and pasta onto his fork.

Frenette, who describes his cooking style at Artemisia as “tried and true food with confidence,” cooked in Maine in the 1990s, then left for California, where for a decade or so he honed his craft under acclaimed chef and restaurateur Paul Bertolli (of Oliveto, Chez Panisse and co-author with Alice Waters of “Chez Panisse Cooking”). Frenette’s wife, Heather Neville, evening front of house manager at Artemisia, was a manager at Chez Panisse. The couple returned to Maine in 2012. Like both Bertolli and Waters, Frenette is a champion of fresh, flavorful cooking.

When was the last time you went out to dinner and every person at the table raved? That’s what happened at Artemisia – three different appetizers, three different entrees, three contented diners. The portions were generous and satisfying, the blend of flavors consistently surprising. And the cooking – whether the supple texture of that octopus or the crispy skin on the chicken – proved both assured and precise. And in an era of restaurant price creep, when entrees routinely veer well north of $25, Artemisia’s prices were reasonable. That’s a smart move for a neighborhood eatery trying to build a base of loyal dinner patrons.

I wish I could say that we also gushed over every item on the dessert menu, but the sweets paled in comparison to the rest of the meal. A bowl of sea salt caramel gelato was store-bought from Talenti, and the accompanying zeppoli, ideally light morsels of fried dough with a blanket of powdered sugar, were heavy. Dessert, alas, was the one weak spot in an otherwise memorable meal, but given the rest, it seemed almost incidental.

On the way to the car I could hear mom’s warning about books and their covers ringing in my ears, but then I had a compensating thought: Being wrong never tasted so good.

James Schwartz has written about food, travel and architecture for several national magazines and newspapers.