Separate the pork ribs and wash them. Cut the bacon into small cubes. Cap and peel the onions at both ends. Halve 1 onion lengthways and roughly chop 1 half. Cut the remaining onions crosswise into rings approx. 5mm thick. Cap the garlic cloves at both ends, peel and cut into thin slices. Wash the carrot, leek and celery. Peel the carrot and roughly chop everything.
Bring the water to a boil and dissolve the chicken broth in it. Add the roughly chopped vegetables along with the ribs and simmer for 20 minutes with the lid on.
In the meantime, fry the bacon in 2 tablespoons of the olive oil in a large pan. Add the onion rings and garlic and fry well until translucent. Strain the broth and use it to deglaze the onion rings. Return to the pot and simmer for 1 hour. Cut off the meat from the cooled ribs, chop up bite-sized and add to the onions. Pass the carrot pieces through a coarse sieve and add the porridge to the onions.
Toast the white bread in the toaster until light brown. Coarsely grate the pecorino. Sprinkle the white bread with it and bake or grill with top heat until the cheese has melted.
Season the soup with the pepper and distribute on the serving bowls. Place the white bread slices in the soup and sprinkle with the fried onions. Serve warm and enjoy.