This is a classic Portuguese dish, popular wherever Portuguese people are to be found. The name comes from the chiles and traditional spice mixture of Angola, a former Portuguese colony. Prepared piri-piri sauce is available in some gourmet shops and on the internet, but you can substitute any hot sauce that you have on hand. The all mighty editor would not let me say "Piri Piri sauce to taste"...so start with a little and add as you can stand the heat. Adapted from Worldwide Recipes.