Preheat the oven to 200°C.
Fry sausages in 1 tablespoon of oil for 3 minutes, then roast in the oven for 12 minutes.
Soften shallots in another tablespoon of oil, then add rosemary and garlic for 2 minutes.
Simmer tomatoes, 60ml stock, and beans for 4 minutes until slightly thickened.
Stir in parsley and season the bean mixture.
Fry pancetta in a casserole dish until crisp, then add the duck meat.
Combine sausages, bean mixture, 275ml stock, herbs, and seasoning, then bring to a simmer.
Grill oiled sourdough slices for 2 minutes per side until golden.
Process bread into crumbs, sprinkle over cassoulet, and bake for 10 minutes.
Boil potatoes for 15 minutes, drain, and dry over heat.
Mash potatoes and beat in butter and cream until smooth.
Serve the cassoulet over the mash.