01 - Pour whole milk over fresh breadcrumbs in a small bowl and allow to sit for 5 minutes until breadcrumbs are softened.
02 - In a large mixing bowl, gently mix ground beef, ground pork, soaked breadcrumbs, eggs, Parmesan, onion, garlic, parsley, basil, salt, black pepper, and red pepper flakes until evenly incorporated.
03 - Form mixture into golf ball–sized meatballs, about 2 inches in diameter, and arrange on a tray.
04 - Heat olive oil in a large skillet over medium heat. Working in batches if necessary, brown meatballs on all sides for about 5 minutes per batch.
05 - Transfer browned meatballs to a large pot with tomato sauce. Cover and simmer gently for 20 to 25 minutes until meatballs are tender and fully cooked.
06 - Serve meatballs hot accompanied by pasta, in a sub roll, or as an appetizer with additional sauce if desired.