In a medium bowl, combine Italian seasoning, Parmesan, garlic powder, salt, pepper and onion, and mix well.
Crumble ground beef and ground pork into a large bowl. Sprinkle seasoning mixture over meat mixture.
Whisk egg and Worchestershire sauce together, and add to meat mixture. Use your hands and mix together until just combined.
Add bread crumbs and continue to mix with your hands until just combined. You don't want to overmix, just get it to the point where the mixture isn't sticky
Use a cookie scoop to form equal-sized meatballs. I use a 1 5/8" scoop. Release scoop into your hands, and roll balls between your palms to shape.
MEATBALL MOZZARELLA SKILLET BAKE
Preheat oven to 375 degrees
Add half of the Easy Homemade Marinara Sauce in a cast iron skillet or baking dish. Top with meatballs. It's okay if the meatballs touch because they will reduce a little as they cook. Cover with remaining marinara
Bake for 10 minutes. Remove from oven, and evenly spread with mozzarella cheese. Return skillet to top rack of oven and bake for 10-12 minutes, until cheese is bubbly