Cut the peppers into quarters and remove the membrane and seeds. Cut the chili in half and remove the seeds. Grill both until the skin is blackened and blistered. Cool in a plastic bag, then peel and cut into thin strips.
Heat the oil in a large saucepan and cook the onion until soft, about 5 minutes. Add the tomato paste, harissa, garlic, cumin and 1/2 cup water, then stir to combine.
Add the fish stock, tomatoes and 2 cups water. Bring to a boil, then reduce the heat and add the fish and bay leaves.
Simmer for 7-8 minutes or until the fish is JUST done. Carefully remove the fish with a slotted spoon and place on a plate. Discard the bay leaves.
When the soup has cooled slightly, add half the fresh cilantro and puree in a blender until smooth. You will probably need to work in batches. Season with salt and pepper.
Return the soup to the pan, add the fish and the pepper and chili strips and simmer gently while you prepare the toasts.
Toast the bread and, while still warm, rub with the cut garlic.
To serve, place a piece of toast in shallow rimmed soup bowls and then pile several pieces of fish on top of each piece of toast. Ladle th soup over the top, distributing peppers evenly. Garnish with the remaining cilantro. Can be served with lemon wedges on the side.