Havana South is a branch office of the original Havana, a Bar Harbor mainstay since 1999. Its success there over the years and this summer, when President Obama and his wife, Michelle, dined there, has no doubt provided the impetus for owners Michael Boland and Deirdre Swords to undertake the expansion south.

And an expansion it is. The Portland restaurant fills a cavernous space with seats for about 160 people. A love of auctions has allowed the owners to fill that wide space with architectural artifacts, including a section of pressed tin ceiling built into a wood frame on wheels that can be used as a room divider. Fabric strips hang over the room’s dividers; they separate one area from another, as do different light fixtures, and most have comfortable booths.

Although the Latino waiters I recall from dining at the Down East Havana in 2007 don’t seem to have filled the staff in Portland, the servers seem to be bantering about huitlacoche and cabrales empanadas with sophisticated ease.

Salsa verde with roasted halibut was one beacon on the menu, and chimichurri and Brazilian red beans and rice improved the classic allure of a seared ribeye steak.

We were overheated during the heat wave, eager to have a drink but too hot and bothered to be able to decide on dinner right away.

So we ordered a bottle of the Jelu Torrontes ($34) from Zonda Valley, an Argentinean white from the list’s page of good wines under $35, and the corn and cabrales empanada appetizer ($9). Cabrales, a Spanish blue cheese, dominated that little empanada, which could have been crisper.

Pureed avocado made a pleasant sauce, and raw red onion in tomato puree was another accompaniment, making the little plate over-busy with flavors. But the acidic and lively wine was altogether satisfactory.

A freebie from the kitchen of raw tuna with spicy chilies on a tortilla chip made a perfect mouthful. And with its help, we were able to settle into decision making. At least at Havana South, the sense that your table time is ticking away did not come up.

Corn bread with jalapeno came warm in a bread basket with a ramekin of olive oil and another of mildly sweet strawberry butter, a graceful match for the cornbread.

Huitlacoche-dusted scallops ($12) wore a coating made with dried, ground corn smut, a fungus that the server more elegantly described as a kind of corn truffle, a prose styling that probably originated at a James Beard Foundation dinner. Darkened corn kernels infected by the fungus are harvested before the fungus fully matures to be dried and ground, then added to foods to impart a mushroom-like flavor.

The scallops we tasted were very mildly flavored by the dark, slightly crunchy crust. A tangle of fresh greens with agave lime vinaigrette was a side that almost stole the show.

Fire and ice shrimp ceviche ($8) was altogether more exciting, with tender-crisp shrimp marinating in a cup of sweet and hot jalapeno and citrus juice, and paired with two mountains of freshly deep-fried tortilla chips, half blue corn and the other half white flour. The white-flour tortilla chips were utterly tender, oily and flakey, while the blue corn tortilla chips were more dryly crunchy — and both were too good to resist.

These appetizers were not small — and when dinner arrived on big generous plates, we were in trouble. “Our Moqueca” ($27) is a seafood stew with lobster, shrimp and mussels enriched with coconut and dende oil, pressed from a kind of palm in Brazil and colored dark and red-orange, which made the seafood dish rich.

The lobster entr?($26) had already been slightly changed, our server said, and was proving popular. Perhaps it was still the effect of the heat, but the best part of this plate was the salad of endive, red onion and grapefruit, which was crunchy, sharp and refreshing.

A grilled split lobster tail wasn’t particularly improved by a bit of charring, but a cup of melted butter with two lobster claws in it made a few marvelous mouthfuls. The “stuffing” of cornbread and chorizo seemed amorphous, and looked unappetizing on the plate.

The promise of gelato from Brunswick’s Gelato Fiasco caught our fancy. Orange chocolate ($6) in a bowl of three big scoops was silky smooth, rich and fabulous. Mexican wedding cookies with Mount Desert Island vanilla ice cream focused more on those crunchy, light and nutty cookies, but that ice cream presented purely flavored indulgence.

Plain decaf ($1.95) stood its ground, strong and slightly bitter. Cuban coffee ($4.95) with evaporated milk repeated the theme of many of our dishes — rich, sweet and strong.

N.L. English is a Portland freelance writer. Visit English’s website, www.chowmaineguide.com.