tom wrote:
Is it possible to grow chillie plants from the seeds of chillies
bought from the supermarket?

It is not impossible that the varieties are "owned" by some seedsman in
such a way that growing them on would infringe a patent or similar
mechansim. This is intended to stop commercial piracy, of course, and
I would expect the packaging to be labelled if this were the case,
although I don't think that is obligatory for the end product food
rather than the growing plants.

And, of course, they might not come 'true'. Many commercial varieties
are F1 hybrids, and the generation you grow will revert to the parents
in some ratio based on good old Mendelian mathematics and the number of
genes involved in any particular characteristic.

And then, it is not impossible that polination has been simulated with
hormones, and the seed will not be viable.

But in the end, vast numbers of seeds in supermarket foods are viable
and worth growing. Wonderful thing, Biology