Ah, the lunch interview—an audition that combines the stress of a job interview with the awkwardness of a first date. To ace it, you’ll need to make a professional impression in a casual environment.

WEST LAFAYETTE, Ind. — Job interviews over lunch or dinner in a swanky restaurant might shock a soon-to-be college graduate more accustomed to guzzling junk food and ramen noodles. But society’s next ...