
In a medium bowl, combine the beef, egg, breadcrumbs, Parmesan cheese, onion, garlic, Italian seasoning, salt, and pepper. Mix until just combined.
With a meat baller or a medium spring-loaded cookie scoop, scoop a rounded ball of the meat, about 1 ½ tablespoons, and form into a meatball. Repeat with the remaining meat mixture. You should get about 20 meatballs. Heat the oil in a large pot over medium heat. Add the meatballs and cook for 5–7 minutes, turning occasionally, until browned on all sides. Remove meatballs from the pot and set aside.
Serve with your favorite marinara.