Pesto is a paste that originated in Genoa, Italy, and is traditionally made by crushing garlic, European pine nuts, coarse salt, basil leaves, and hard cheese such as Parmigiano-Reggiano or Pecorino Sardo, all blended with olive oil. The name "pesto" comes from the Genoese verb "pestâ" which means "to pound" or "to crush," in reference to the original method of preparation. The ingredients are "crushed" or ground in a marble mortar through a circular motion of a wooden pestle. Nowadays, pesto can be made using a food processor, which allows for the incorporation of herbs or vegetables that may be tougher than basil.

The traditional ingredients for pesto are fresh basil, pine nuts, garlic, salt, Parmigiano-Reggiano or Pecorino Romano cheese, and olive oil. However, there are many variations of pesto, some traditional and some modern, as the very noun pesto is a generic term for anything that is made by pounding. Some variations include using coriander, dill, kale, mint, parsley, rocket, spinach, or wild garlic instead of or in addition to basil, and using artichokes, black olives, green olives, lemon peel, lime peel, or mushrooms.

Pesto is a versatile sauce that can be used in many ways. It is commonly served with pasta and chicken sandwiches, but it can also be used as a spread on bread, a topping for pizza, a dip for vegetables, or a sauce for meat, seafood, or rice. Pesto is a delectable sauce to toss with any kind of pasta, thick enough to cling to every noodle, elbow, and twist. It can also be used to bring flavor to other dishes, like soups, roast chicken, grilled cheese, and homemade pizza.

In summary, pesto is a paste that originated in Genoa, Italy, and is traditionally made by crushing garlic, pine nuts, salt, basil leaves, and hard cheese with olive oil. It is a versatile sauce that can be used in many ways, and there are many variations of pesto that use different ingredients.