To cut the meats, roll up the pork rind like a Swiss roll. With the seam underneath, use a very sharp knife to cut the roll across into thin slices, then chop the rolled-up slices across into dice. Chop the bacon into small cubes (lardons). Cut the garlic sausage into 1cm thick slices.
Drain the soaked beans and discard the soaking water. Tip the beans into a large saucepan, add the diced pork rind and lardons and cover with fresh cold water. Bring to the boil and blanch for 15-20 minutes. Drain the beans, rind and lardons into a colander, and discard the cooking water.
Roughly chop the celery, onion and carrot. Peel the garlic cloves but leave them whole. Cut each tomato into eight wedges. (You never see tomatoes in a traditional cassoulet, but chef Raymond Blanc likes them for their colour and sweetness, so he puts a couple in.) Preheat the oven to 120C/fan 100C. (If cooking in a gas oven, use mark 2.)
Heat the goose fat or olive oil in a 26cm flameproof casserole or deep overproof sauté pan over a low heat and sweat the celery, onion, carrot and garlic for 5 minutes. Add the tomatoes and bouquet garni and cook slowly to get a sugary caramelisation (about 5 minutes). Add the sausage, beans, pork rind and lardons and pour in 1.2 litres/2 pints water. Bring to the boil, skim off the scum, then add the salt, pepper, clove and lemon juice.
Transfer the casserole to the oven and cook, uncovered, for 2 hours, stirring every hour. At the end of this time, the beans will be soft and creamy in texture and the juices should have thickened. You may need to cook it for longer than 2 hours (say up to 2½ hours) to get to this stage – it depends
Remove the cassoulet from the oven. Bury the duck legs in the beans and sprinkle over the goose fat or olive oil, breadcrumbs and garlic. Return to the oven and cook for a further 2 hours. Serve the cassoulet in bowls, sprinkled with chopped parsley.