How to keep slow-cook pork/beef juicy after freezing?

If I could cook them fresh every time, I would, but it does take a lot of time. Usually, I cook a big batch, let it cool at room temperature, then portion it into food containers and freeze it. When I want to use it, I defrost it in the fridge, then either pan-fry it or sometimes deep-fry it if I’m making skewers. I’d like to ask: how do restaurants keep slow-cooked pork or beef juicy after freezing, and what’s the best way to reheat it to maintain its juiciness please? submitted by /u/k999rrl