Heat the olive oil in a large heavy-bottomed soup pot. Add the bacon and the onion and saute for about 3 minutes.
Add the carrot, celery, leek, and pepper, stir well and saute, stirring often, for about 5 more minutes.
Add sweet paprika to the vegetables, stir well for one minute.
Add the stock, tomatoes, sugar, thyme, one teaspoon salt and ½ teaspoon freshly ground black pepper.
Stir well and bring to a boil. Turn the heat down to medium-low and simmer, covered, for about 10 minutes.
Add cabbage and bring to a boil again. Simmer for 5 minutes, add the meatballs and drained black beans and simmer for another 15 minutes or until the vegetables are tender and the meatballs cooked through.
Add 1 teaspoon red wine vinegar and more salt and pepper to taste. Add the remaining red wine vinegar according to your taste.
Serve immediately or reheated.