Peel the potato and chop it into small cubes, then boil in slightly salted water for about 5 minutes.
Finely chop the onion and add it in a large pan drizzled with olive oil. Fry it at high heat for 1 minute then add the rice and the shredded Savoy cabbage (remove the thick white center from the leaves). Once the rice is toasted (about 2 minutes) pour the white wine and let the alcohol evaporate. Reduce the heat to low.
Cover the rice with the stock and add more stock when it's completely absorbed. Halfway through the cooking, add the diced potatoes.
When the rice is almost done, remove it from the heat and add a knob of butter and the Parmigiano cheese. Mix well and set aside.
In a small pan quickly brown the bacon at high heat (it should not be too crispy though), then add it to the rice and mix. Add also the roughly chopped mozzarella.
Transfer the rice into a baking pan or individual cocottes and cover with enough breadcrumbs. Add small curls of butter on top.
Bake at 200°C (440°F) for about 10-15 minutes or until golden on top. Serve immediately.
You can substitute the bacon with Italian sausage in this recipe.