There may be plenty of fish in the sea, but if you're wondering which kind are best for stewing, you should follow this ...
Eels are a traditional ingredient in the typical French freshwater fish stew, Matelote. They’re also very popular in Spain, particularly as elvers (which are generally served deep-fried).
Conger eels are sometimes used to make Caldeirada, a Portuguese fish stew. They are also popular in South America, Japan and China.