Preheat the oven to 220C.
Chop the pepper and onions into large chunks and put on a greased baking tray.
Roast for 15-20 mins until blackened and soft.
As soon as the vegetables are removed from the oven, put in an airtight food bag and allow to sweat for 5 mins.
When cooled, remove the blackened skins and add to the soup maker. We added another chilli at this point once but the soup was much too spicy - you might be braver than us though!
Add the stock, water and chopped boiled potatoes and turn soup maker on.
If you are cooking the soup in a pan, add all the ingredient to a lidded pan, bring to the boil and simmer for 10-15 mins. Then blend.
Add salt and pepper to taste.