Heat the milk in a small pot until steamy. Turn off the heat, tear the bread into little pieces and soak it in the milk until it partially dissolves. Mash it until you get something that resembles a paste. Turn it out onto a plate to let it cool.
In a large bowl, combine the beef, pork, ricotta cheese, grated parmesan, eggs, salt, parsley, oregano, black pepper, garlic cloves and the bread-milk mixture. Mix it well with your hands until it barely combines. Don't overwork the mixture or it will become tough. It is OK to have some discernable bits of bread or meat in the mix; better that than overworked meatballs.
Wet your hands and form the meatballs. A traditional size for this sort of meatball is 2-3 inches across, but you can make them any size you want. Once you roll the meatball in your hands, roll it in the flour to give it a good coating. Set each one on a baking sheet as you work. You might need to rinse your hands a few times as you make the meatballs.
When all the meatballs are formed, heat olive oil in a large skillet over medium-high heat. Brown the meatballs on at least two sides. Don't worry about the center getting cooked through, as you will finish these in the sauce.