Foods from the homeland became springboards for invention in the States. Take pizza, which evolved from its simple Neapolitan roots into styles unlike anything found in Italy (see Any Way You Slice It), with more cheese, more sauce, and more toppings. Or, tomato sauce, for that matter: When my wife and I first traveled across Italy, on our honeymoon in 1977, we saw neither marinara (that quickly cooked sauce of just tomatoes, garlic, and oil) or the long-simmered "Sunday sauce," stocked with all kinds of meats, which most families I knew while growing up served on Sunday. Of course, tomato sauce exists in Italy; the irony is that tomatoes were brought to Italy from the Americas in the 16th century and considered poisonous by all but southerners, who found them a delicious addition to their meager diet and discovered that they flourished in their sunny clime. Which explains why when more than 4 million Italians, a vast majority of them from the south, immigrated to America between 1890 and 1910, they brought tomatoes, and tomato sauce, with them. Every cook had a version, and it became the food on which immigrant mothers staked their eminence within their neighborhoods. Growing up, we would no more insult a friend's sauce than we would his mother or grandmother. The sauce was sacred.