Might be too much faff, but a 'cheat's cassoulet is good.
Fry the sasuages until lightly browned all over in a heavy-based casserole or deep oven-proof pan.
Remove sausages and add a couple of chopped rashers of bacon to the pan (smoked is best). Fry gently to render out the fat.
Remove bacon and add a finely-sliced onion to the pan. Sweat until turning transluscent (if I have them, I will also add a finely diced carrot and stick of celery with the onion). When the onion becomes see through, add a couple of finely chopped garlic cloves (or a squirt of garlic puree/teaspoon of 'lazy' garlic) to the pan and cook for 2 minutes more.
Add a good squirt of tomato puree to the pan and cook out for about 5 mins.
At this point I sometimes add half a teaspoon of smoked paprika, but it is entirely optional.
Now add either a couple of cans of drained borlotti or cannelini beans, or a can of each, or a can of one and a can if baked beans. Also add a can of chopped tomatoes, a squirt of tomato ketchup, a bayleaf and season. Taste a little of the sauce - you may want to add a teaspoon of sugar to counteract the acidity of the tomatoes, although if you are using carrot, baked beans and tomato ketchup you probably won't need to.
If I have any open, I'll also add a glass of red wine.
Put the sausages and bacon back in the pan and simmer the whole lot until the sauce has reduced and is coating the beans and the sausages with a bit of extra, thick sauce, rather than being too liquid.
Meanwhile, whizz some stale white bread (any kind will do and I leave the crusts on) with some flat-leaf parsley together in the processor to make fairly coarse breadcrumbs.
Sprinkle a thick layer of breadcrumbs over the sausage and bean mixture, drizzle a little olive oil over the top and either pop into a hot oven or under a medium grill until the topping is nicely browned.
Serve with a green salad with a mustardy dressing.