Roast the Peppers
Rub oil on peppers and char them over a gas flame or under the broiler until blackened on all sides
Put them in a paper bag and let them rest for 10-15 minutes before peeling, seeding, and slicing (** If using canned roasted peppers, rinse them well in a colander and set them aside to drain)
Soup
Warm oil over medium heat in large stockpot. Add the onions and sauté for about 15 minutes, until the onions are very soft and translucent.
Add the garlic a pinch of salt and sauté for another minute or so
Remove the pot from the heat and add the tomatoes, coconut milk, water, and the roasted red peppers.
Purée soup with a hand blender. Alternately, working in batches, use a conventional blender or food processor. I like a little chunk and texture to this soup particularly if the weather has a bit of a chill, but smooth or chunky, it's up to you
Return it to the soup pot and cook on medium heat until hot
Add the cheese, and red pepper flakes (or cayenne pepper, if using), along with a bit more salt if needed - adjusting to your taste.
Serve topped with croutons, cheese, and/or slivered basil