Step 1 Preheat oven to 180ºC. Mix ginger, ground coriander and oil in a bowl. Add lamb and toss to coat evenly. Leave to marinate in the fridge for at least 4 hours.
Step 2 Place onions in boiling water for 2 minutes. Drain and refresh in cold water. Peel and halve. Set aside.
Step 3 Spray a frying pan with oil. Cook lamb in batches over medium heat until evenly browned. Add garlic. Cook for 2 minutes.
Step 4 Place lamb in a flameproof casserole dish and stir in flour and paste. Add onions, tomatoes, wine, herbs, stock, cinnamon stick, bay leaf and rosemary (if using). Bring to the boil. Remove from heat. Cover, then cook in the oven for 1 1/4 hours, stirring occasionally.
Step 5 Discard cinnamon and bay leaf. Add dates and return to oven for 15 more minutes. Top with low-fat natural yoghurt and a sprig of mint. Serve with basmati rice or couscous and steamed vegetables.