Shake Shack CEO Rob Lynch often visits his restaurants without announcing himself or his position.

Instead, he’ll have a seat, grab a meal and observe what’s going on around him, Lynch told CNBC in an interview for an episode of “Leaders Playbook,” a series set to premiere on Wednesday. He wants to see both a generally welcoming environment, and a team of employees that are energized by their work, he said.

“If I’m really lucky, I get to sit there and see a [general manager] interviewing a prospective team member,” said Lynch. “They’re not asking them, ‘Have you ever made custard shakes before?’ or ‘Have you ever sliced tomatoes?’ They’re asking them about what motivates them. What do they love to do for fun? How do they interact with people?”

Lynch, who was the CEO of Papa John’s prior to joining the global burger and milkshake chain, and his general managers want to hire employees who “light up when they’re taking care of others,” he added.

Similarly, Shake Shack founder Danny Meyer looks for employees with six specific emotional skills, he told “Leaders Playbook”: integrity, optimism, intellectual curiosity, work ethic, empathy and self-awareness.