From Giada De Laurentiis on the Today Show, with a couple of modifications. Prep and cooking times are estimates, but I find that from start to finish I need about 1.5-2hrs to make this dish. Also, I have found the meatball mixture to be too wet when using 2 eggs, but my mom never has trouble with that, so I put a step into the directions to use 1, mix, and check to see if it's too dry before adding the second egg.
If you make this earlier in the day, place in a 150-200* F oven and hold for up to 3 hours. The mozzarella gets all melty and delicious. (FYI, any size of mozzarella balls are fine, so long as it's 8oz of fresh mozzarella. I've used bocconcini, 8oz balls, ovoline, and ciliegine.)
The prep is a bit intensive (mostly getting the meatballs together and made). This is a popular enough dish in our house that I now make the meatballs ahead and freeze them. If making meatballs ahead, do not add the broth or tomatoes, just brown the meatballs, bag, and freeze. When I use frozen meatballs, I just defrost them, start a pan going with the broth and tomatoes, and then add the meatballs and continue from there.