I'm in no way suggesting that anyone reheat in a microwave...(this deviates away from the OP...but is in response to a couple of posts above)
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But if that method yields bad, or in some instances admittedly your worst result, then you have no idea how to use a microwave (or you think hitting one button should fix all your problems). Common sense goes a long way.
A microwave can perfectly heat up barbecue. I do it all the time.
Can it mess it up beyond what I would eat? Yes it can. Having the aforementioned common sense goes a long dam way to not letting it get to that point.
Heat, stir/rotate...heat, stir/rotate...heat, stir/rotate.
I freeze food (barbecue) with four things in mind. Ease of freezing, storage, speedy thawing, and if needed, microwaving. One thing aids in achieving all of these things...freezing flat & as thin as possible. Plastic bags are needed in order to realize these goals. Place the food in the bag so it's not sitting in a blob in the bottom...spread it out, utilize the entire bag (or at least a portion of it that allows you to get a flat profile). Once flat it will 1) freeze quickly so that you can move it to storage, 2) store easily because it is flat & hopefully somewhat thin, 3) thaw quickly, again, because it is thin, 4) thaw in the microwave easily from a frozen state.
I do NOT fully reheat in the plastic bag via the microwave. Once thawed I remove from the bag for further heating. I do NOT microwave for extended periods. On single portions I typically reheat for 15-20 seconds, stir/turn, 15-20 seconds, stir/turn...
Microwaves reheat beautifully, if you choose to use it properly.