Pesto
This is a sauce to have on hand at all times. It keeps well in the refrigerator for at least a week if you film the top of it with olive oil (and refilm after you have dipped into it and taken some from the jar), and it keeps its bloom for a couple of months frozen. It’s a good idea to freeze it in an ice tray, and then store the cubes in plastic storage bags. That way, you easily can get at just the amount you need.