Next time, try placing a sliced in half hard boiled egg along
with your piece in a plastic bag and leave it for some time. The
longer the darker.
This is true - and I've found it works best if the egg is warm. If
it's not, just throw it into the microwave for a few seconds. And if
you squash the yolk into the piece (yucky to clean, but not
difficult--just rinse), the oxidation is more controllable and is
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