Yesterday we went cloths/shoe shopping, did gardening etc and the last thing I wanted to do was cook. Realising it was getting a little late and having some pork fillet to use up, we decided to chop everything up small and make a 'quick' curry.
Everything was brought to the boil but in my hurry, I don't think I did the initial stage long enough.
Anyhow, 3 hours later we opened up the cooker, the pan was red hot. For the whole of the cooking period I had been smelling polystyrene but didn't think anything of it.
We lifted out the pan, then the silicon sheet and found that there was a saucer sized, melted disc of polystyrene sitting on top of the balls in the lower pad. To top that, the tea was only half cooked. My fault completely, but what could we do, the monthly shop is near, not a lot in, so we ate out at a nearby pub.
I read the Wonder-bag site (mine is home made and not a Wonder-bag) and they suggest that if you use a cast iron pan, that a folded tea towel, oven gloves or heat proof material is put on top of the bottom cushion (if you see what I mean).
The first two meals had been fine, and appeared to be at the same temperature so I don't know why it happened this time, but it did. Working on the proviso that there is no such thing as a mistake, only a lesson, we warmed the pan up again to boiling, sat it on a folded tea towel and silicon sheet and closed up the bag.
Another 3 hours went by in the bag but by then, it was 9pm and too late to eat. The pan was sat in a sink full of cold water to cool down enough to put in the fridge. This morning I put 3 long foil cartons of it into the freezer and we shall eat the remainder tonight.
You live and learn my friends. Anyhow, I do have a different saucepan but it has a glass lid (apparently not the best style to use) but luckily, the cast iron one fits on top of the pan. Next time, we shall try this combination.