Jeremiah begins pursuing a culinary career at the end of The Summer I Turned Pretty season 3.
The development appears in the finale, “At Last,” after the wedding storyline has ended and Jeremiah starts moving forward independently. The episode presents this as part of his attempt to build a future beyond the romantic conflict that has defined much of the series.
Jeremiah’s new direction contrasts with several other careers shown in the season. Conrad remains connected to medicine, Steven develops his startup with Denise, and Belly continues college work while living in Paris. Jeremiah’s final professional path is therefore culinary rather than financial or academic.
The answer is best stated as “culinary career,” not as the name of a specific restaurant or job title. The episode summary identifies the field Jeremiah moves into, but does not establish a narrower official position.