Pesto been used for all sorts of cold sauces or dips, mostly without any of the original ingredients: arugula (instead of or in addition to basil), black olives, lemon peel, coriander, or mushrooms. In more northern countries, ramson leaves are sometimes used instead of basil. In the 19th century, Genovese immigrants to Argentina brought pesto recipes with them. A Peruvian variety, known as "tallarines verdes" (meaning "green noodles", from Italian "tagliarini"), is slightly creamier, lacks pine nuts (because of their rarity and prohibitive cost in Peru), may use spinach and vegetable oil (in place of olive oil), and is sometimes served
Tomato sauce roux). All of these qualities make them ideal for simple and appealing sauces. In countries such as the United Kingdom, Australia, New Zealand, and South Africa, the term "tomato sauce" is used to describe a condiment similar to ketchup. In some of these countries, both terms are used for the condiment. The use of tomato sauce with pasta appears for the first time in 1790 in the Italian cookbook "L'Apicio moderno", by Roman chef Francesco Leonardi. The simplest tomato sauce consists just of chopped tomatoes cooked down (possibly with olive oil) and simmered until it loses its raw flavor. Of