I bake spuds in my Aga.
Funnily enough last night I was doing one for Mrs Clint Bint but it was so big that even after an hour it was still hard inside.
So I halved it,nuked it for five minutes,then olive oiled the two open halves and bunged them back in the Aga for ten minutes.
Finished off with melted cheese and chilli flakes.
A few baked beans and voilá herself was fed for less than a quid.
Result.