Ravioli (perhaps a diminutive of Italian dialectal rava, or turnip) is a type of filled pasta composed of a filling sealed between two layers of thin pasta dough. The word ravioli is reminiscent of the Italian verb ravvolgere ("to wrap"), though the two words are not etymologically connected. The filling may be meat-based (either red or poultry), fish-based, or cheese-based. Ravioli can be rectangular, triangular, half-moon or circular in shape. Other traditional Italian fillings include ricotta mixed with grated cheese and vegetables such as spinach, swiss chard, or nettles or they may be a puree made of potatoes, mushrooms, pumpkin, chestnut or artichokes. A version filled with sweet potatoes is popular in contemporary Israel. Ravioli is often topped with a red tomato-based sauce: though tomatoes were introduced to European botanists in the 16th century, tomato sauce makes a surprisingly late entry in Italian cuisine: in 1692.  More delicate fillings are often paired with sage and melted butter, or more rarely with pesto- or broth-based sauces. Cream sauces are foreign to Italian traditional cuisine. Though the dish is of Italian origin, the oldest known recipe is an Anglo-Norman vellum manuscript from the 1290s.. Sicilian ravioli and Malta's ravjul may thus be older than North Italian ones. Maltese ravjul are stuffed with irkotta, the locally produced sheep's-milk ricotta, or with gbejna, the traditional fresh sheep's-milk cheese. In Venice, the mid-14th century manuscript Libro per cuoco offers ravioli of green herbs blanched and minced, mixed with beaten egg and fresh cheese, simmered in broth, a recipe that would be familiar today save for its medieval powdering of "sweet and strong spices". In Tuscany, some of the earliest mentions of the dish come from the personal letters of Francesco di Marco Datini, a merchant of Prato in the 14th century. In Rome, ravioli were already well-known when Bartolomeo Scappi served them with boiled chicken to the papal conclave of 1549. Preparation of home-made ravioli with ricotta.Today, ravioli are made in worldwide industrial lines supplied by Italian companies such as Arienti & Cattaneo, Ima, Ostoni, and Zamboni. "Fresh" packed ravioli usually have seven weeks of shelf life. Similar foods in other cultures include the Chinese jiaozi or wonton â€“ in fact, ravioli and tortellini are collectively referred to as "Italian jiaozi" (????) or "Italian wonton" (?????)) â€“ Eastern and central European pierogi, the Russian pelmeni, the Ukrainian varenyky, the Tibetan momo, the Turkish manti, German Maultaschen, and Jewish kreplach. In Lebanon, a similar dish called shishbarak contains pasta filled with minced beef meat and cooked in hot yogurt.