In a large shallow frying pan, fry off the sausages at a medium heat until lightly browned. Set them aside.
Now fry the onions until just brown before adding in the garlic for another minute.
Add the pancetta and fry for 5 minutes, stirring frequently to avoid burning the garlic or onions.
Pour in the white wine and continue to cook on the hob for 7-8 minutes.
Now pour the wine, pancetta, garlics and onion into a casserole dish along with the sausages, herbs and chicken stock. Place the dish, lid on, into the oven and cook for 3 hours.
30 minutes before the cassoulet is ready to come out of the oven, set to work on the potatoes. Peel them and chop into medium sized pieces (as you would for roast potatoes). Place in a pan of cold, salted water and bring to the boil. Simmer for 15-20 minutes, lid on, or until they feel soft whilst still retaining a tiny bit of bite when prodded with a fork.
Whist your potatoes are boiling, add the kale and cornflour to the cassoulet and stir through before returning to the oven.
When the potatoes are done, drain them in a colander before returning to pan (off the heat), adding the milk and butter and mashing (preferably with the mash attachment of a hand blender, but by hand is fine).
Finally stir in the Tartufata truffle sauce before taking the cassoulet from the oven and serving up over a generous scoop of the mash.