Lentil soup with smoked sausage

1. Melt the butter in a large saucepan, add the onion and sauté until soft and transparent. Rinse the lentils under the cold tap and drain well.
2. Add carrots, apples, lentils and seasoning to the onion mixture. Sauté for 2 minutes before adding stock and bay leaves; bring to a simmer.
3. Cover pan with a lid and continue to simmer for 45 minutes or until lentils and carrots are quite tender. Stir occasionally – so as to incorporate the apple pieces that will break up whilst cooking.
4. With a slotted spoon, lift half the vegetables into a food processor or blender. Cover and whiz to a purée, then return to the saucepan.
5. Slash the smoked sausages and add to the soup. Return pan to the boil and simmer for 10 more minutes.
6. Cut sausage in portions before serving with garlic croûtons.