Heat the oil in a sauté pan and colour sausages all over to acquire some colour. Then remove and set aside.
Peel and halve the onions and cut into crescent slices, about 1cm wide at the thickest part. Sauté these in the pan in which you cooked the sausages until soft but not coloured.
Add the pancetta and cook over a higher heat and give bacon a good colour and slightly singe the tips of the onions
Add the celery and chilli and cook for a further minute
Throw the lentils and pour on the wine and stock. Bring to the boil.
Season, turn down to simmer and put sausages back. Don’t let the lentils get too soft - keep testing them. The stock and wine should get absorbed by the lentils. Add more if needed.