In the moments before a wedding, or after a date's cryptic texts, or when a friend reveals their love for an insufferable band, it's only natural to ask yourself, "Can we ever truly know a person that well?"

The same thing can be said of our food world. There are some dishes that feel so familiar we assume we know everything about them.

So it's exciting and humbling when a place such as Darlinghurst's La Farmacia comes along and makes you question your "expertise" on Mexican cooking. 

Hidden behind a sandwich shop, this taco and margarita joint is the brain child of Alfredo Perez and Anthony Macfarlane – two friends who met on a surfing trip in Guadalajara.

The duo trades as Mrs Palmer by day, where they serve up oversized, made-to-order carb wonders. By night, the venue turns into a vibrant eatery that produces some of the tastiest Guadalajaran-style tacos in Sydney. 

Perez, who heads up the kitchen, hails from a large family of food lovers and cooks. To get his tacos right, he spent weeks Facetiming his loved ones in Mexico for recipes and tips.

This fierce pride for regional cooking shows in his menu, where the simple street snack is treated with as much care and respect as any celebrated national dishes. 

"Mexico is so incredibly diverse," says Macfarlane. "There's a lot of Mexico City cooking in Sydney, but not as much regional cuisine." 

This is why you'll see things such as the lamb barbacoa – a slow-cooked lamb shoulder so soft that the meat hangs like fine ribbons on a tortilla. In Oaxaca, the dish is usually made with a whole beast barbecued day-long in an underground pit.

Here, the spirit of the – barbacoa is preserved with an eight-hour slow roast and the smokiness is recreated with imported guajillo chilli. Like the old school version, it's served with a small cup of consomme – either to be sipped or to dip your taco in.

Another highlight is the al pastor taco, which is made from pork shoulder that's been moulded into a "trompo" or a spinning top, and cooked on a vertical spit. Similar to a shawarma, the meat is shaved thinly and served on a palm-sized tortilla.

Pieces of roasted pineapple accompany the rich meaty topping which has been marinated overnight in a deep red achiote (Mexican spice mix) paste. 

For an extra carb hit, go for the spicy chorizo and fried potato tacos. Or opt for a veg-friendly topping (the only one for now) with the pan-fried mushrooms that has a burnt-pepper sauce kick.

All tacos come with house-made salsas (red and green) and are spliced with a healthy sprinkle of fresh herbs and chopped onion. 

Like most Mexican eateries, expect a line-up that's big on meat. But if seafood is more your speed, the ceviche menu offers a compact, but impressive selection with hard to find specialties such as the aguachili.

This cured prawn dish hails from the north-western state of Sinaloa, and is a popular hangover cure. You'll see why with the punchy lime, coriander and jalapenos dressing. And yes, it's served with fried, crispy warm tostadas.

An accompaniment that also comes with the excellent market fish ceviche. 

Wash down your favourite taco or zesty cured fish with one of the 16 specialty margaritas – grouped under the classics, the spicy, the fruity and the botanical.

You can't go wrong the a classic marg, but there's something to be said about a picture-perfect elderflower and pink grapefruit version with a tea leaf rim. 

And you're right to assume there's a Taco Tuesday, where you can feast on Perez's creations at half price.

But at $5 a pop every other night already – is there much point in waiting? 

The low-down

La Farmacia 

Main attraction: Affordable Guadalajaran-style tacos that are made with care and inspired by chef Alfredo Perez's family recipes.

Must-try dish: The lamb barbacoa taco, which comes with a consommé you can dip your taco in. 

Insta-worthy dish: Go for the colourful aguachili. The cured prawn dish hails from the north western state of Sinaloa, and is served with a bright, zesty dressing. 

Drinks: Wine by the glass $10; beer $8-$10; margaritas $15-$22