2) Add the garlic and cook for 2 to 3 more minutes. Remove from the heat and cool.
3) In a large bowl, combine the meats, rosemary, Parmesan, water, breadcrumbs and eggs. Season generously with salt and add the cooked onions and garlic. Combine until well mixed.
4) Make a small ball of the meat mixture. Cook it and eat it; this is a tester meatball to check if the seasoning is correct (it may need more salt). Adjust the seasoning, if needed.
5) Roll the meat mixture into 2cm meatballs. Coat a large frying pan with olive oil and place over a high heat. Working in batches, cook the first batch of polpettini until they are brown on all sides.
6) Add 120ml of chicken stock and cook until the stock has reduced by half. Remove to serving platters. Repeat this process until all the polpettini are cooked. Serve immediately. Buonissimo!