Chicken soup, Greek penicillin (!), is one of the most delicious winter dishes. Most people know it in its restaurant interpretation, as chicken soup avgolemono, with rice and the classic egg-lemon liaison. This old recipe, from northern Greece, calls for trahana, a delicious, sour grain product that is one of the oldest agricultural products in continuous use throughout Greece and the Balkans. The tartness of the trahana makes up for the absence of lemon in this unusual soup. To find trahana and other great Greek ingredients, go to my online store here.