Tomato & sourdough soup

Yotam’s mother, Ruth, who kindly gave us this recipe, is in many ways a typical Jewish Jerusalem cook. She was born to a Yekke family, German Jews who settled in the city just before the Second World War. Growing up, she spoke German at home and ate sweet-spiced red cabbage, potatoes and sausages. Outside, she would experience some Arab food — it tasted thoroughly exotic to her — and the fo