A stay interview is the exit interview you hold while there is still time to act. Ask a few of these in a relaxed one-to-one, or send them ahead as a short form so people can think before you talk. Then change at least one thing.
We've ticked a short starter set. Change it to suit you.
What keeps you here
What might make you leave
Growth and recognition
Workload and support
Me as your manager
6 questions selected
Tips for a better stay interview
Hold stay interviews with your strongest people first. They have the most options.
Listen more than you talk, and don't defend or explain while they answer.
Pick one thing you can change within a month, and tell them when it's done.