Pesto is a thick green sauce from Italy made by crushing fresh basil leaves, garlic, pine nuts, olive oil, and cheese into a smooth paste. The name comes from the Italian word pestare, which means “to pound” or “to crush,” because traditionally you make pesto by grinding the ingredients together in a bowl with a heavy tool called a mortar and pestle.

The most famous kind is pesto alla Genovese, which comes from Genoa, a city in northern Italy. When you taste real pesto, you get the fresh, slightly sweet flavor of basil mixed with the nuttiness of pine nuts and the sharp taste of Parmesan cheese. It's bright green and very aromatic.

People most often toss pesto with pasta, where it coats every noodle in flavor. You can also spread it on sandwiches, stir it into soup, or use it as a dip. Some cooks make variations using different herbs like cilantro or parsley, or swap pine nuts for walnuts or almonds. While these creative versions can be delicious, traditional Italian cooks would say that pesto alla Genovese must have basil and come from that specific region of Italy.