How do you hire a general/operations manager from outside your business?

We have multiple units and have been in business for 40 years. Up until now, we’ve always been able to promote from within. I’m not saying that times have changed that much, just that we’re having a drought of employees that aspire to make a career out of managing a location. Last month, I had a manager that runs one our stores quit with no notice. We’ve been able to patch up the holes temporarily, but I still don’t have any long term prospects on the horizon. This means that I’ve been spending a lot of time at the location that would be better spent at our headquarters/wholesale warehouse.

I’m wondering if anyone here has experience with hiring a person to run all operations at one of their stores. I would still handle the finances and we would review together.

How do you hire employees for this kind of position? It seems like a huge risk to pay someone well that you don’t know very well.