My engine shuts off sometimes when I’m slowing down.

I have a 2010 Ford Escape XLT. In the next couple of days after I put gas in my tank, my engine will shut off as I’m slowing down. As I apply the breaks (sometimes not always) my battery light will turn on followed by the oil light, then the engine will shut off entirely. When I turn the car off then on again it will start up like normal. My mechanic has had my car for days and can’t get it to shut down as I experience it to. The alternator is brand new so thats not an issue, I’m frustrated because we can’t quite figure out what is wrong. Has anybody else experienced this?