At first sight, Forest Avenue in Portland plays host to miles of gray shopping centers. A commuter might think twice about stopping at a Forest Avenue eatery for an after-work meal or a beer during happy hour; the traffic is fast and the storefronts pass by in quick, blurry succession.

But for those who live here – eat here, drink here – Forest Avenue isn’t just a main thoroughfare to the next town. If you look hard enough, ask around and take a chance, this road leads to many good things.

There’s an Iraqi bakery that churns out warm pita and sweet baklava, a Thai restaurant that some might say makes the best pho in town, a Cajun restaurant with an outstanding breakfast menu and a loyal customer base.

And in January, smack in the middle of a relentless Maine winter, a Mexican restaurant entered the fray. Casa Fiesta is a chain, yes, but only second to the existing Casa Fiesta in Biddeford. Owned by a Pennsylvania-based corporation, Casa Fiesta on Forest Avenue has its sights set on bringing house-made margaritas and reasonably priced Mexican food to Portlanders.

For starters, this place is an enormous sight to behold. An unknowing passerby likely won’t notice the size of the restaurant – akin to a cabin-like ski chalet or an old Western train station, Casa Fiesta chose the second location of its “party house” appropriately.

Inside, Casa Fiesta is exactly what you might expect – kitschy, corporate – but a spot to sip an authentic margarita or a cold Dos Equis while devouring free house-made chips and salsa? You’ll forget about the silly decor in seconds.

The staff is pleasingly friendly and attentive. They’ll greet you immediately with menus.

Toward the back is the bar, away from the main hubbub of the restaurant. While the bar lighting is somewhat obtrusive and tacky, the bartender is eager to get drinks mixed and orders cooking. A large basket of tortilla chips will arrive seemingly out of nowhere, along with a bowl of salsa and queso.

In keeping with the cheesy, commercial nature of this Mexican oasis, the menus, including the drink menu, are laminated binders full of funny options. Many of the drink offerings include an exclamation mark or hyperbole like “Best beer in the city!” when there’s just one local beer listed – Shipyard.

There are seven options for margaritas, which include the house-made margarita, a spicy berry margarita, a margarita made with Corona and a pomegranate margarita (surprisingly delicious).

The bartender will slip a large margarita glass from the rack and ask you with a smirk if you’d like the regular or grande size. The regular house margarita is $7.25 and looks like it could quench the thirsts of two adults. The “grande” is $9.25 and is so big it could likely satisfy a small group, such as a bachelorette party. But rumor has it people often drink the grande margarita solo.

The margaritas are popular – Portlanders have been trekking out to Forest Avenue just to try them. For people less inclined to order a sweet tequila beverage the size of a kiddie pool, a number of options remain.

House wine is $4.50 and there are six other wine-by-the-glass options from $6.25 to $7. Mojitos come in three variations (pomegranate, mango and classic) and at the back of the menu is a list of 16 types of tequila – not the longest list in town but a notable one.

Other cocktails include the Hawaiian Magic, Tequila Sunrise, Bahama Mama and Red Apple Sangria.

If the wait staff at Casa Fiesta were not so courteous and outwardly happy, the place might be a bust. The margaritas would start to taste bad if your affable bartender didn’t care about refilling your basket of chips. The awkward lighting would suddenly seem rude, and the atmosphere, while conveniently spacious, might begin to seem superfluous. But because Casa Fiesta strikes a key of lightness and fun – they don’t take themselves too seriously – things taste better.

On Friday and Saturday nights, more people swarm the restaurant for fast, authentic and relatively cheap Mexican-American food. There will even be a roaming Mariachi band.

Casa Fiesta is a welcome addition to Forest Avenue’s string of eateries and would be a good choice for families, groups or someone looking for a grande margarita. It might be an easy place to poke fun at, but don’t knock it ’til you try it.

Claire Jeffers is a Portland freelance writer.