Stir regularly, until almost completely melted, then remove from the heat.
Cook over a low heat for 5-6 minutes, stirring regularly.
Season, to taste, with salt and simmer for 12-15 minutes, stirring regularly.
Fry for 6-8 minutes, stirring regularly, until browned all over.
Return to a simmer and cook for a further 2-3 minutes, stirring regularly.
Add the stock and simmer, covered, for 30 minutes, stirring regularly.
Continue to heat, stirring regularly, for 10-12 minutes, or until the beans begin to break down.
Bring to the boil then turn down to a simmer and cook for about 15 minutes, stirring regularly, adding more stock as it's needed.
Cook for 2-3 minutes, stirring regularly, or until golden-brown on all sides.
Continue to boil for 1-2 minutes, stirring regularly, until the sugar has dissolved.