This is one of my childhood favorites. I grew up in southern Massachusetts where there is a huge portuguese population. We would go to the coast and collect any muscles, clams or periwinkles we could find and then toss them in a pot once we got home. These days a trip to the supermarket works okay. Feel free to add whatever seafood you'd like. Ingredient amounts are estimations since we really just threw whatever we had into a large pot. Make sure the clams and mussels are fresh and discard any that don't look so great.