The addition of vinaigrette to freshly roasted vegetables gives them a freshness and juiciness they don't normally have; the acidity brings out new shades of flavour, too.
I keep returning to the combination of artichoke, broad beans and lemon. The freshness of young beans and the lemon juice 'lifts' the artichoke and balances its hearty nature.
There is a unique freshness when eating buckwheat noodles cold with plenty of herbs and citrus acidity. I can't think of any better use of chopsticks on a hot and sweaty evening.
Barberries, or zereshk, are tiny dried red fruit with a tremendously sharp flavour. They come from Iran, where they're used to add freshness to rice and chicken dishes.