02/21/2014 04:38 EST | Updated 04/23/2014 05:59 EDT

Alex Stupak went from pastry chef to savory cuisine because his clock was ticking

MIAMI BEACH, Fla. - Alex Stupak was 27 when he said his biological clock started ticking.

But that's jumping ahead. First, you need to get better acquainted with this once avant-garde pastry chef who felt he could better express himself creatively through high-end tacos. Yes, you read that right. He's the sort of guy whose intellectual sides makes it hard for him to stay on topic. He's the sort of guy who loves a good analogy, particularly in reference to his unusual career trajectory (cue the ticking clock).

The way he describes it, he dreamed of having a restaurant by the age of 30, but he didn't want just any restaurant. He wanted to make sure he pushed himself creatively. So Stupak — who stunned the culinary world with his pastry creations in some of the nation's most cutting edge restaurants — abandoned pastry for slinging tacos.

And that's when this Food and Wine magazine "Best New Chef" went from molecular gastronomy — using liquid nitrogen and fancy foams — to rustic Mexican cuisine. He saw it as a "blood in the water" moment.

"Once you get into that repetition, it's factually no longer creative," he said of his days of making foams and crazy desserts. "It's about pushing you to do something you don't know how to do."

Why Mexican cuisine? The pure challenge of it.

"It's misunderstood. It's the underdog," he said Friday during an interview at the South Beach Wine and Food Festival. Initially, he figured he'd start with tacos because they would be easy. Except he learned they were very much not easy.

"What made it more difficult is we did it simultaneously with opening a restaurant," he said referring to his hot spot Emepellon Taqueria in New York City. "Learning something completely new in the pressure of the kitchen is difficult, adding on that you are actually the owner and you are in charge of every facet of the kitchen."

Stupak, originally from Massachusetts, appears minimally on television — he says he gets nervous on camera but he is working on that. He also hates whistling, worked at Denny's back home and makes a mean omelet.

Back to his ticking clock: Mission accomplished. Stupak, who is now 34, plans to open a third restaurant in September.

"I thrive on adversity and doing that thing that other people couldn't do," he said.