This week's buzzword is pistachios. It's not really fair to limit them to a week, though. They've been used for over 2,000 years by various cultures and grow more fashionable by the day. There is something very therapeutic about cracking them from their shells. Yes, you can buy them shelled, but, like podding broad beans, there's a pace to it. Their bright green hue is gorgeous and swirled through egg white and sugar they make stunning meringues. Use them in place of ground almonds in cakes - they are a little heavier, but you will end up with a deep, moist cake to serve for dessert. Try making a brittle with them instead of peanuts - ground down, scattered over ice cream. Heaven.