Preheat the grill to medium and line a baking tray with tin foil. Prick and add the sausages to the tray, then cook for 10 minutes, or until browned all over, turning halfway through. Remove to kitchen paper to drain. Trim, wash and chop the leeks. Trim and finely slice the celery, peel and finely slice the garlic and deseed and chop the red peppers. Heat a lug of oil in a large ovenproof casserole pan over a medium heat, add the leeks, celery, garlic and red pepper and cook for around 10 minutes, or until the leeks start to soften, stirring regularly. Next, add the spices and cook for a further 2 minutes, then add all of the remaining ingredients, draining the beans first, along with a splash of water. Stir everything together well, then push the grilled sausages under the surface of the passata and bring everything to the boil. Turn the heat down to a simmer and continue to cook with a lid on for a further 45 minutes. Regularly check that it isn’t getting too dry while it’s cooking – you can always add a splash of water if it is. Have a taste and see if you think it needs a splash more vinegar, then pick, roughly chop and scatter over the parsley (if using). Delicious served with baked sweet potatoes or brown rice and a nice chopped green salad.