Fish chowder

In a large saucepan, cook the onion and potato in the oil over a medium heat for 5 mins to soften. Add the stock, cover and simmer for 10 mins until the potatoes are just tender. While the potatoes are cooking cut the haddock into chunks and break the mackerel into large flakes, discarding the skin. Blend the corn flour with a little of the oat drink and add to the pan with the sweet corn, peas and remaining oat drink, then bring to simmer. Now add the fish and cook gently for 10 mins. Stir in the cream and heat for a few mins, season if needed. Ladle into bowls and serve with crusty bread.