Dave wrote:
>
> Hi ! First time posting... got a question:
> Just curious if I'm the only person who chops up onions and stores
> them in olive oil...
> I have a small cafe and I wanted to find an alternative to frying the
> onions to speed up service, so I tried leaving them in seasoned olive
> oil in a tupperware container overnight...
> the result is that it softens the onions, then when I toast the
> sandwich the olive oil adds seasoning to the bread and a nice
> aftertaste.

Did anybody mention botulism? :-)

I doubt that botulism would be a problem if the onions
are kept under refrigeration the whole time, and the
whole time was only a day.

As an alternative, vinegar might be a good choice.
There's no botulism risk (which occurs with oil
because it cuts off access to the air), and the
vinegar should be more aggressive in breaking
down the onions. You also might consider blanching
the onions before marinating.

Also, the vinegar will pick up flavor from the
onions, and may find uses of it's own.