Iranian onion soup from Winter Food by Jill Norman

Ingredients

• 1 1/2 litres vegetable stock or water
• 4 tablespoons sunflower oil
• 2 tablespoons plain flour
• 4 medium to large onions, halved and thinly sliced
• 1 teaspoon turmeric
• 1 tablespoon dried fenugreek leaves
• salt, to taste
• juice of 3 lemons or 4 limes
• yogurt, to serve (optional)
• 1 teaspoon crushed dried mint, to garnish
• 2 eggs
• sugar (optional)
• ½ teaspoon ground cinnamon