Mexican food has always been fun, but now it's getting serious as well. What used to be Tex-Mex is now more Mex than Tex. Closer to the real thing. Made with real Mexicans and Australians, working together.

It could have gone the other way, down the cheesy enchilada road – but it didn't. We're now seeing eateries focused on regions such as the Yucatan Peninsula, Oaxaca (Wahaca), Mexico City.

They're in beachside suburbs for the playa atmosphere, and do well on the North Shore, where legions of teenagers grew up on surfing from Taco Tuesdays to Corona beer Friday nights.

St. Alma's Jack Leary and Tim Christensen are part of that journey. Leary used to hang out at Manly's Chica Bonita, where Christensen was chef. They joined forces to open Alma in Avalon four years ago, and have now expanded to Freshwater.

Their first job was transforming a former bank into a contemporary space, fringed by kitchens, bars and picture windows to the street. Mission accomplished. St. Alma looks and feels great.

They've been working remotely with new chef Maximo Martinez before his arrival from Mexico City this month, to create a "coastal Mexican" menu.

Yes, it starts with the money-spinning "guac and chips" – of course it does – but goes on to sikil pak, a toasty Mayan pumpkin seed dip, soft-shell crab tortillas, chilli octopus, corn truffle empanadas, agave short ribs and banana leaf fish.

The window-side booths are the best seats in the house, tables are flanked with wicker or bentwood chairs, lighting is clever, and staff are savvy. Drinks are taken seriously, but while six different margaritas and a variety of tequila and mezcal cocktails are offered, most still go for the classic marg.

A likeable, interesting, multi-layered wine list runs with a focus on chardonnay and shiraz, and there are plenty of booze-free drinks as well. (Freshy even has its own no-alcohol bottle shop Sans Drinks, directly opposite Vintage Cellars.)

A Tommy's margarita of reposado tequila, agave and lime ($18) is fresh and feisty, ready to take on crisp little hard-shell tacos of salmon, avocado, pico de gallo salsa, jalapeno and lime, scattered with black sesame seeds like ants at a picnic.

Tortillas are the more flavourful corn variant, sourced from La Tortilleria​ in Melbourne, and the soft tacos that utilise them are designed to be more than a mouthful of meaningless pap. An al pastor ($7) has the requisite slow-cooked, marinated pork belly teamed with grilled pineapple and watermelon radish; meaty and satisfying.

It's tempting to stay with the snacks all night. A tiradito of kingfish-like amberjack ($19) ticks the ceviche box, but it's the crisp chicken tinga empanadas ($15) that get my undivided attention. The shells are impressively thin, made in-house from imported masa, and the shredded chicken in chipotle and tomato sauce is warm and balanced.

A pleasant dish of halloumi comes off the grill with an agave and thyme caramel ($18) and a generous shower of nutty, crushed praline; not quite sure why.

The one larger dish I try is of confit duck ($39) with black beans, spinach and clumps of Oaxaca cheese made by Marrickville's Vannella, topped with crisp sweet potato straws. It probably works better on paper than it does IRL. While the confit technique is good and the separate elements are fine, there's no oomph, acidity, contrast, or anything to bring it together.

For dessert, los coconut churros ($18) has become something of a signature for both Alma and St. Alma, and I can see why. The extruded churro is the sugar-dusted doughnut of your dreams, shaped into a bowl that holds a soft coconut gelato squiggled with chocolate and more crushed nuts.

Ambitious owners who want to expand people's perceptions of Mexican cuisine; a place you want to hang at on the way to or from the beach; and Mexican chefs doing hands-on Mexican food that's built for sharing over a drink or two? Sounds like serious fun.

The low-down

Vibe Fresh-as Mexi-cantina with cocktails

Go-to dish Al pastor pork belly taco, $7

Drinks Margaritas, tequilas, Mexican and local beers and strong Australian-led wine list