Iron deficiency is a big health issue in Cambodia where nearly half the population is iron deficient.
It's a major cause of anaemia which mainly affects women, teenagers and young children causing tiredness, headaches and serious problems in pregancy and childbirth.
Treatment with iron tablets can be expensive and they are not easily available. So Christopher Charles came up with a simple solution based on ancient technology; a small piece of iron shaped like a fish that gets added to the pot while you're cooking.