Pesto is great to have under your repertoire. It can be whipped up in five minutes and flavoured with just about anything you like. For a bright verdant green pesto, I like adding spinach, as well as a few red chilies for a bit of a kick.
I usually use pesto for pastas, and occasionally as sandwich spread, but it also works well in a puff pastry tart with mozzarella and tomatoes.
Spinach Pesto: In food processor, take 1 cup of baby spinach, 1/2 cup of toasted almonds, 2 cloves of garlic, 1 small red chili pepper (seeded), a handful of basil, and 1/4 cup of olive oil. Pulse until smooth.