Recipe November! Sossij and tomato casserole

1 onion, chopped
2 tbs groundnut oil
6 sausages
200ml cider
50g tomato puree
4 sundried tomatoes, chopped finely
4 carrots, peeled and chopped
4 sticks celery, chopped
100g red lentils

Heat the oil in the bottom of a heavy saucepan, and brown the onion and sausages. Then cut the sausages into chunks (I stick my kitchen scissors in the pan to do this) and stir in all the other ingredients. Add more cider or water if needed to cover the vegetables. Simmer gently for about 45 minutes until the lentils are soft, season to taste and serve with mashed potato.