Passata is made from ripe tomatoes that have been puréed and sieved to remove the skin and seeds. It's sold in jars and can be smooth or chunky depending on the level of sieving.
It's useful to keep in the cupboard to use in soups, sauces, pasta dishes, casseroles, or anything that needs a concentrated tomato flavour. Passata is also great for using in drinks with a tomato base, such as Bloody Mary. Once opened a jar will keep in the fridge for up to a week.