Line cook is the most consistently open role in Brooklyn food service. Kitchens are usually hiring, which means speed matters more than polish -- the job often goes to the first competent person who follows up.
Apply in the afternoon, in person, and ask for the chef or kitchen manager by role. Front-of-house staff will not know the kitchen's hiring situation. Afternoon prep time is when the chef is reachable and not yet on service.
Expect a stage, or trial shift, rather than an interview. You will be asked to work a few hours, often unpaid for the first one, so the chef can watch your knife work, your pace and whether you keep your station clean. Bring your own knives and a clean set of blacks. Show up early.
Say which station you can actually run -- grill, saute, fry, garde manger. Being specific reads as experience; saying you can do anything reads as neither. If you are new, apply as prep cook or dishwasher and say you want to move to the line. That path is short in Brooklyn kitchens and chefs promote from inside constantly because turnover is high.
Get a food handler's certificate first. It is inexpensive, takes an afternoon, and some kitchens will not put you on the schedule without one.
Ask about the schedule before you accept. Line cook hours are nights, weekends and holidays, and the commute matters when you are getting out after midnight -- check the late-night subway service from the restaurant to your apartment, not the daytime trip.