THE TWO HOUR RULE
I was reading this thread with some interest yesterday and since things were quiet at work I did some searching for advice on leaving cooked food at room temperature.
It seems that there is a 2 hour rule whereby you don't leave cooked food at room temperature for more than 2 hours before refrigerating or freezing. After this time the amount of bacterial growth just increases rapidly. Apparently cooked vegetables (i.e. base sauce) are a real magnet for bacteria. The situation would be even worse if you used meat stock in your base.
Now I know (in advance - hello Phil

) that many of you will have survived such episodes with no harm but that may not be true for everybody that you plan to feed. I found a thread on Chowhound where people were discussing this subject and certainly a few people got sick from leaving cooked food out all night. Usually it is an accident and has happened to me, like making a 4 portion chilli and forgetting to put the half leftovers in the fridge before bed. I binned the food the next day, much to my annoyance, and I didn't know about the 2 hour rule then.
Ignore this advice if you wish but it is the official line on food safety.
Stay safe folks!

Cheers,
Paul