A coomon bivalve mollusc found throughout the world usually attached to rocks or man made objects that appear at or near the water line. Most have dark blue/black shells that can be as large as 8cm in length. buy them alive in their shells, or the cooked meat in frozen bags, in brine, canned or smoked. mussels are highly farmed and so they are readily available.

Note - Discard any that are open and won't close when tapped prior to cooking, also discard any that remain closed at the end of cooking.