Put stock – which should be home made reasonably clear and not over salted, in a saucepan and start heating gently while you wash the dried cepes (porcini in Italian) in a sieve.
Add the cepes to the stock and when boiling turn down to a very gentle simmer. Don’t cover and allow to simmer until reduced to 2/3 volume. Strain and allow to settle as the cepes always give out a little sand no matter how carefully you wash them.
When ready to serve, decant from the sediment, reheat and season. Add the optional madeira and serve.
