Warm the oil in a large saucepan. When shimmering, add the onion, garlic, ginger, and chilis, and cook on medium heat until softened, about 5 minutes.Add the rest of the ingredients except for the cayenne, black pepper and salt, stir well, and bring to a boil. Reduce heat to a simmer. Cook for 20 minutes, stirring occasionally.Remove the bay leaves and fresh herbs. Season with cayenne pepper, black pepper, and salt to taste (and more of the other spices as well, if desired). This soup should be salted rather aggressively if you are serving it with fufu, which isn't salted at all.