New Zealand is a large producer of mussels from the South Pacific, so the New Zealanders sure know how to cook them. Make them their way for guaranteed sweet, plump mussels every time. Please note that whenever we cook mussels, they need to be cleaned first. To clean mussels for cooking, wash them under running water and scrub away any grit or barnacles with a stiff food scrub brush. Remove the black "beard" from each mussel by cutting or pulling it off.