In a large kettle, add potatoes, onion, celery ribs, garlic and carrots. Add bay leaf (remove before serving). Cover with water and bring to a boil, then simmer until vegetables are tender, about 15 minutes.
Add butter and fish. Continue cooking until the fish flakes easily, about 10 minutes.
Add milk, parsley, salt and pepper. Heat thoroughly before serving.
Servings: 4