Melt the butter in a heavy bottomed saucepan with the spices and cook over a medium heat for 3 minutes. Add the vegetables and stir to combine, cook for a further 8 minutes. Add the lentils and the rice, fold in before adding stock. Bring to the boil and simmer for 30 minutes - or until the vegetables are tender and the lentils have started to break down.
Blend the soup in a liquidiser until smooth. Return to the heat, add coconut milk, lime juice and coriander. Heat through but do not reboil.
Per serving: 524 Calories (kcal); 28g Total Fat; (46% calories from fat); 11g Protein; 62g Carbohydrate; 21mg Cholesterol; 2078mg Sodium Food Exchanges: 2 1/2 Grain(Starch); 0 Lean Meat; 3 1/2 Vegetable; 0 Fruit; 6 Fat; 0 Other Carbohydrates