I've seen Italian Wedding Soup recipes where you place the raw meatballs in the hot broth to cook them. I did not want to do this for two reasons. First, I love meatballs that are brown and crispy on the outside. You won't get this if you drop the raw meat into the broth. Second, I like to make my meatballs with ground pork and beef, but both release a fair amount of fat when cooked. I would rather pre-cook the meatballs in the oven and drain off the fat than have all that fat dissolved in my soup.