I dry the whole lot (I don't use stem) and grind it down fine
then into a big pot then add butter 1 oz per 200 g butter
melt it down for six hours on the BBQ
then strain through a stocking then into the fridge
when hard take out of pot and wrap with gladwrap and into the freezer until ya wanna get fucked
You can just get a pot and put some water in it...then put the butter in...then put in all of your grinded trim / leaves. Stir on low heat for an hour and a half. Then sift it through a cheese cloth. Let the water / butter harden. The butter hardens at the top and is easy to separate. Enjoy.