Add the panko bread crumbs to a large bowl and set aside.
In a skillet over medium heat, melt the butter.
Add the finely chopped onion, salt, pepper, allspice, and nutmeg and cook for about 5 minutes. Stir often.
Add the minced garlic and cook for another 2 minutes.
Turn the heat down to low/medium, and add the milk. Stir everything together and bring it to a simmer.
Once the onion mixture has come to a simmer, pour it from the pan into the bowl of panko bread crumbs and stir everything together. The mixture will be very thick. Set this bowl aside to cool.
In a separate extra large bowl, add the eggs and beat them.
Then add the ground beef, ground pork, and cooled onion mixture. Mix everything together. (It’s gross, but it’s easiest and quickest to do using your hands.)
Form about 30 balls and then chill them in the refrigerator for 30 minutes.
Once the meatballs are done chilling, in a large skillet over medium heat, heat up the oil.
Add the meatballs to the skillet in batches and cook them until they are browned on all sides, about 15 minutes. Batches made it so the pan wasn’t over crowded which made flipping them and seeing when they were done easier.
Transfer the meatballs to a dish and set them aside.
Directions for the Pasta:

Cook the pasta al dente according to the directions on the box, drain it and add it to a 9 x 13 oven safe baking dish.
Directions for the Sauce and Assembly: