The portuguese sauce is a hearty tomato sauce made with sauted onions, garlic, tomato concass and parsley. Tomato concass (pronounced "Conk-a-say") is a fancy culinary term to describe tomatoes that have been peeled, seeded and roughly chopped. This recipe calls for 1 quart of the classic tomato sauce, which is one of the five so-called mother sauces of the culinary arts. You could instead use 1 quart of basic tomato pasta sauce, which is easier to make.