The word gnocco means "lump", and comes from nocchio, a knot in the wood. It’s been a traditional Italian pasta type of probably Middle Eastern origin since Roman times (Imperium Romanum). It was introduced by the Roman Legions during the enormous expansion of the empire into the countries of the European continent. In the past 2000 years each country developed its own specific type of small dumplings, with the ancient Gnocchi as their common ancestor. In Roman times, gnocchi were made from a semolina porridge-like dough mixed with eggs, and are still found in similar forms today, particularly in Sardinia. One variety, gnocchi di pane (literally bread noodles), is made from bread crumbs and is popular in Friuli and Trentino-Alto Adige/Südtirol. The use of potato is a relatively recent innovation, occuring after the introduction of the potato to Europe in the 16th century.
Gnocchi are widely available dried, frozen, or fresh in vacuum sealed packages in supermarkets and Italian specialty stores. Classic accompaniments of gnocchi include tomato sauces, pesto, and melted butter (sometimes fried butter) with cheese.
At the start of the 20th century waves of European immigrants arrived to Latin America. In Argentina, over 50% of those immigrants came from Italy, and they brought their traditions and cuisine along with them.
In Brazil, Argentina, Chile, Paraguay, Uruguay, and Venezuela, countries where Italian cuisine is especially popular, gnocchi (known as ñoquis in Spanish-speaking countries or nhoque in Brazil) are traditionally eaten on the 29th day of each month. Argentines, Paraguayans and Uruguayans gather each month (exept february) specifically to eat "ñoquis del 29" (literally, "gnocchi of the 29th"). On these occasions, some people leave a banknote under the plate to attract prosperity. There are two popular explanations for these customs. One is that 29th is the day before payday, when money was tight and gnocchi were cheap and hearty fare. The other is that the 29th is the feast day of Saint Pantaleon, one of the patron saints of Venice, who was canonized on this date. Pantaleon was a doctor in the 8th century who, upon converting to Christianity, made a pilgrimage across Northern Italy. Along the way, he practiced miraculous healings that led to his sainthood. On one occasion, he asked some poor farmers for a little bread, and they invited him to share their meager meal. He blessed the farmers, who reported abundant crops the next year-another miracle. Eating simple food (represented by the ñoquis) on his feast day is the customary way to honor that miracle and ask for prosperity and blessings.
In a curious reversal of meaning, in Argentine and Uruguayan slang ñoqui has also become a way to denote a government employee that is listed in the payroll but only shows up to collect his or her paycheck around the 29th of each month.