For the Polpetti, finely dice the bacon and mix with tomato paste, mustard, oregano, marjoram, minced meat, breadcrumbs, egg, salt and pepper and a little milk. The mass should be compact, but still have a bond. Possibly add more breadcrumbs or milk. Let the mixture rest in the refrigerator for 10 minutes.
Cut the mozzarella into cubes about the size of a teaspoon. To shape the Polpetti, take approx. 4 heaped teaspoons of the meat mixture in the moistened palm and press flat. Place a piece of mozzarella in the middle, seal and shape into a ball. The mozzarella should be well enclosed without the balls becoming too big. I usually have a little left over from a Mozarella ball.
Heat the oil in a saucepan and fry the Polpetti in portions one after the other. I always take a small wok, about 200 ml of oil, turn the polpetti and make them 2-3 times, keeping the finished meatballs warm in a baking dish in the oven.
In the meantime, cook the maccheroncini according to the instructions. I think they fit well because the cavity allows them to absorb the sauce particularly well. If I have a lot of time, I make strozzapreti myself. Mix the cooked pasta with the sauce and possibly some pasta water and serve immediately.
Place the pasta with the sauce on a plate, loosely distribute the Polpetti on top and sprinkle with plenty of freshly grated Parmesan. Garnish with basil if necessary.
Variant:
Mix a buffalo mozarella, torn into small pieces, into the pasta.