Is there any method of doing small amounts of charcoal in a common gas stove?
You can make it on any reliable heat source, in a sealed container such as a biscuit tin, with small vent holes in the top to let out the waste gases. The only problem with using a normal gas stove is that it can only be made in small amounts, and it MUST be made outside. The smoke/gas produced from it are both flammable and smell awful, so make sure you are in the garden, with the windows closed and there is no clothes on the washing line!
I use a camping stove for small amounts but it gets expensive to keep buying gas cylinders, so it is best to make a wood fire and use that to make a large amount. I'm not allowed to make fires in the garden though so until I go camping next time I am stuck with buying expensive gas cylinders, or using ready made charcoal.
Is your stove inside or is it portable?