I roasted a joint of beef in the slow cooker about a month ago, we ate half and I put the rest in the freezer (cooked) last week I took it out to turn into a pie I added loads of mushrooms and veg, stock etc there was too much for the pie dish so I put it into little Tupperware containers and froze it again. Can I defrost it and feed it to them again or is cooking something 3 times no good? I know it's dull to keep eating the same thing but is it safe!?