Cut the bacon into fine strips and fry briefly in the hot butter. Add the onions and leek, cut into rings, fry until translucent and pour in the broth. Add the diced potatoes and the carrots cut into thin strips, season and cook for 10 minutes.
Then add the cleaned Brussels sprouts and cook for another 15 to 20 minutes. It should be done, but still have bite. Let the sausages soak in it for the last few minutes. Season well and sprinkle with parsley if desired.