In a large pot over moderate heat combine oil, crushed pepper, anchovies, garlic, and bay. Let anchovies melt into oil. The anchovies act as a natural salt, the pepper flakes will infuse the oil, providing heat.
Chop celery and onion near stove and add to the pot as you work. Saute vegetables for a few minutes to begin to soften and add wine to the pot. Reduce wine a minute, then add chicken stock, tomatoes, thyme, and parsley. Bring sauce to a bubble and reduce heat to medium low.
Season fish chunks with salt and pepper. Add fish and simmer 5 minutes, giving the pot a shake now and then. Do not stir your soup with a spoon after the addition of fish or you will break it up. Add shrimp, scallops, and mussels and cover pot. Cook 10 minutes, giving the pot a good shake now and again.
Remove the lid and discard any mussels that do not open. Carefully ladle stew into shallow bowls and pass bread at the table.