I came across with a really great article by Claire Lew that talks about six ways to get employees talking about what they really feel (and not what they think you want to hear)…
on an one-on-one with an employee.

The article covers the next topics:

• Make empathy your mission.
• Ask questions to uncover two things: tension and energy.
• Admit what you think you suck at.
• Explain why you need their input.
• Don’t get defensive.
• Talk less.

Here is the link to the article: How to have an honest one-on-one with an employee

I really hope you find this information useful.