Heat 15ml oil in a large frying pan over medium heat. Add the pork belly, season with salt and pepper and brown well all over. Place in a large casserole or stockpot.
Add the sausages to the frying pan and brown them well all over too. Cut each sausage in half and add to the casserole.
Add the onions and carrots to the frying pan and cook for 12-15 minutes until the onions are soft and golden. Stir in the garlic and cook for 30 seconds, then add the wine and simmer until reduced by about half. Add to the casserole and stir in.
Put the tomatoes into the frying pan with a dash of oil and cook for about 5 minutes until they start to soften and colour. Place in the casserole, add the herbs and stir to combine.
Add the beans to the frying pan with the stock and season. Bring to a simmer, then tip them over the ingredients in the casserole to form a layer on top of everything. The beans should be barely covered with the liquid.
Cover and cook in the oven for 40 minutes. Remove the lid and bake for another 20 minutes.Meanwhile, put the bread on a baking tray and toast in the oven until it’s dry and crisp. Let it cool, then blitz in a food processor to crumbs.
Take out the cassoulet and turn the oven up to 190°C. If there’s still liquid on top of the cassoulet, ladle some off before you add the crumbs. Scatter the breadcrumbs evenly over the top in a thick layer.
Sprinkle the rest of the oil over. Return to the oven uncovered and bake for 30-40 minutes until breadcrumbs are browned and crisp.