Cioppino is a fish stew made with tomatoes and several kinds of fish and shellfish. It was created by Italians in San Francisco.
Clean mussels just before cooking, since they die when debearded. Scrub with a stiff brush under cold, running water. Remove beard (dark threads protruding from shell) by pulling towards hinge or pointed end of shell using fingers and a dry towel.
For ease when serving, remove two-thirds of the mussels from their shells and discard shells. Ladle stew into serving bowls and garnish with the remaining mussels in the shell.