If you're looking for the best burger in Mexico, it might just be the one served up by this Kentucky native at a small restaurant in Puerto Vallarta.

Walter Thomas, an Elizabethtown native, and his business partner Carlos Avila have crafted a niche dining spot in the bustling Romantic Zone of Puerto Vallarta with their restaurant Derby City Burgers.

The menu screams Louisville, with some burgers aptly named "Derby," "Bluegrass BBQ" and "Slugger." Their logo features a behemoth burger with a toothpick boasting a fleur de lis inside a horseshoe.

They even have a small bourbon selection - which is a serious feat in Mexico. "You can always find Jim Beam or Maker's, but every once in a while, I have been able to find some Woodford Reserve or Bulleit bourbon," Thomas told me as I sat at a small red table under a patio covering at the come-as-you-are restaurant during a recent vacation. "Fortunately, the reposado tequilas and añejo tequilas are aged in oak barrels. It is obviously not the same thing (as bourbon), but makes for an easy transition."

So how did two friends, who met working at a restaurant in Louisville, Kentucky, end up opening a burger shop in a popular Mexico resort town?

Chance.

Avila grew up in a small town south of Mexico City and moved to Louisville in 1994, where he graduated from Seneca High School. He met Thomas while the two men worked at Rafferty's - Thomas as managing partner and Avila as food supervisor - in the early 2000s and struck up a friendship over their shared love of travel.

"On my many trips to Mexico, I would usually pick a beach town to visit. I would mix up the different spots, but Vallarta kept calling me back," Thomas said. "The hotel we would stay at was next door to this Indian restaurant which was never open. One time passing by, I mentioned to Carlos that it would make a great burger spot."

Two years later in 2011, that oft closed storefront became Derby City Burgers. The friends wanted to open the restaurant quickly - in time for a high travel season - so they wrote a small menu of one or two appetizers and eight different burgers. It evolved from there.

"The idea of doing a burger restaurant came about because after eating tacos every day while on vacation, I really craved a big ole juicy burger, but I felt most were subpar here," Thomas said.

So, he created his own. And the inspiration behind the burgers on their menu is much like what any good chef would say - it's based off what Thomas and Avila enjoy eating.

"If we didn't come up with them - [think a mushroom and Swiss burger] - we tried to make them better," Thomas said. And they don't disappoint.

The menu boasts mouth-watering creations - with beef imported from America - like the aptly-named "The Slugger," a beef patty layered with onion rings, BBQ sauce and honey mustard, "The Casa," which serves up a little kick with fresh chilies and pepper jack cheese, or "The Derby," its namesake burger that is topped with lettuce, tomato, onions, pickles, mayo, mustard, cheese and bacon. (Bonus: you can also add a fried egg for 10 pesos - which is roughly $.50.)

The menu is rounded out with a handful of salads, wings and other appetizers, a selection of chicken sandwiches, a few different types of (crisp!) fries and local spirits and beer.

Since opening about seven years ago, they've moved to a larger location down the street to accommodate more dine-in customers.

"We are very fortunate to have a great following," Thomas said. "I think that has a lot to do with our clients realizing that we don't skip on quality."