An Italian dark green sauce for pasta originating in Genoa. It's made from pine nuts blended with fresh basil, parmesan or pecorino cheese, garlic and olive oil.
Red pesto is made similarly but is based on either sun-dried tomatoes or grilled red peppers. It's uncooked and can be bought preserved in jars or fresh in tubs. The contents of jars, once opened, should be kept in the fridge and used within a couple of weeks. Keep the surface covered with oil. Fresh pesto in tubs should be used within two to three days. It can easily be made at home but you do need a generous amount of basil leaves to make just a small portion of pesto.
Variations include using rocket, watercress or parsley instead of basil and nuts such as walnuts, hazelnuts or pistachios instead of pine nuts.
The sauce can be stirred into freshly cooked pasta, spooned onto thick soups, spread on bruschetta, fillets of fish or chicken before grilling, or added to mayonnaise and salad dressings.