Line a baking sheet with parchment paper or aluminum foil.
Add the bread crumbs to a small bowl and add the milk. Let the breadcrumbs soak for 20 minutes.
Add olive oil to a skillet over medium heat.
Add the chopped onion and cook for 6-8 minutes until the onions have softened. Stir as needed so the onions don't burn.
Add the chopped garlic and continue to cook for 1-2 minutes. Remove from the heat and set aside until needed.
Preheat the oven to 400 degrees F
Add the ground beef and pork to a large bowl and mix until blended together.
Line a baking sheet with parchment paper and spread the ground meat mixture out on the baking sheet.
Add the cooked onions and garlic, bread crumb mixture, Parmesan cheese, parsley, salt, and black pepper.
Press the seasonings and other ingredients into the meat.
Pour the lightly beaten eggs over the mixture.
Lifting the parchment paper by the sides, fold the meat over on top of itself.
Place the mixture back into the large bowl and finish mixing the ingredients together. Be careful not to over-mix, or the meatballs will be tough.*I use this method of spreading out the meat to help distribute the seasonings and other ingredients without over-mixing. You can, of course, just mix everything together in a large bowl. Form the mixture into balls about 1 ½ inches in diameter. Place the raw, formed meatballs in a single layer on the prepared baking sheet.
Place the baking sheet on the center rack of the preheated oven and bake for 15-20 minutes or until an internal temperature of 165 degrees has been reached.