Oil a 8cm x 25cm shallow baking tray.
Put the water and stock into a medium size pan and bring to the boil. Reduce to a simmer.
Gradually add the polenta and pepper, stirring constantly.
Simmer for about another 10 minutes until the polenta thickens.
Stir in the butter and any optional extras, then spread the polenta into the baking tray.
When it has cooled place in the fridge for about 2 hours or until firm. It can be frozen at this stage to be baked or fried off when needed.
Heat the oil in a pan and deep-fry in batches until browned.
Cut the polenta into chips of your desired size.