Melt the butter in a casserole dish and brown the onion for 5 minutes, stirring. Add corn and diced potatoes, cayenne and paprika. Cook for 3 minutes over medium heat. Add the peppers and stock and bring to boil. Reduce heat and simmer for 20 minutes.
Liquidize the soup and stir in the cream. Taste and adjust seasoning as necessary.
Garnish with coriander leaves, pepper slices and a few sweetcorn kernels and serve immediately.