Okay so hands up, this thread should be called "the one with the hay box". As I have mentioned in other threads, I read "Swallows and Amazons" as a child and during the pandemic remembered their hay box. Its basically a way of slow cooking that uses zero energy after the food is initially brought to a boil. I made my own, and it has saved us a lot of money, plus we can use slow cooker recipes without a slow cooker, deversifying our diet.
What have other Mumnetters remembered or discovered that is a money saving tip from a slightly off piste source?