Cut the kernels off the corn cobs
Heat the butter in a large saucepan over medium heat
Add the corn kernels, capsicum, onion, and chili and stir to coat the vegetables in the butter
Cook, covered, over low heat, stirring occasionally for 10 minutes or until the vegetables are soft
Increase the heat to medium and sprinkle with the flour, stirring for a further minute.
Remove from the heat and gradually add the vegetable stock, stirring together
Add 2 cups of water and return to the heat
Bring to a boil then reduce the heat to low and simmer, covered, for 30 minutes or until the vegetables are tender
Cool slightly
Ladle about 2 cups of the soup into a blender and purée until smooth
Return the purée to the soup in the saucepan, pour in the vegan sour cream and gently heat until warmed through
Season to taste with salt