Catalan fish stew

Fish soups and stews are common all over the world, but for me the French bouillabaisse and the Spanish soups and stews are the best. This dish can be served as a hearty soup or a main course or fish course stew. The thickness can be adjusted to suit by adding some fish stock to thin it down. You can make this from scratch, but I find the use of a good fish soup for the base (Instead of merely fish stock) improves it immensely. (I freeze some from the last batch of fish soup I made.)