It’s on to the Next chef for Grant Achatz’s celebrated rotating-concept restaurant (953 W. Fulton Market, West Loop, 312-226-0858), as chef de cuisine Jenner Tomaska has been promoted to executive chef, replacing Dave Beran. Beran, a Food & Wine best new chef who’s helmed the Next kitchen since it opened in 2011, is heading to Los Angeles to open his own restaurant. His last dinner service was April 17.

The 29-year-old Tomaska, who’s a first-time James Beard award finalist this year, wasn’t surprised about the shuffle.

“Me and Dave are close,” he says. “I knew his goals and things he wants to achieve. It wasn’t a shock [that he was leaving], more like this is the day we are announcing it. I had known before we started the [current] Alps menu, so I was heavily involved in Alps. Dave kind of helped me write this menu and almost switched roles and supported me as I had done with him.”

Tomaska’s first solo menu will be South America, debuting April 30. Admitting that “approaching a whole continent for a menu is nuts,” the menu will rotate through Peru, Argentina, and Chile.

“Each month, we will change the template of the way the menu is written, and the flavor profiles will change,” he says. “For instance: shaved ice is big in Peru, and purple corn would be a flavor profile in Peru. Chile and Argentina have something similar, but in Chile, instead of pouring syrup, they use jam or compote. In Argentina, mulled wine.”

Tomaska has worked alongside Beran and Achatz in Next’s “close-knit” kitchen of 12 for almost five years, starting as a morning prep cook on the second menu (Thailand), working 16-hour days peeling carrots and potatoes.

Tomaska first met Beran at MK, where the two worked early in their careers. Though he says he has “huge shoes to fill,” spending the past four years as Beran’s sounding board has prepared him. As has being a bit type A. “I’m very, very organized,” he says.

He may have graduated from peeling potatoes long ago, but we’re betting Tomaska has plenty of 16-hour days in his future. “I’m always one of the first in and last out,” he says. “I like being at work, and I like what I do.”