In a large bowl, combine the breadcrumbs and milk. Let them soak for a few minutes.
Add the ground beef, grated Parmesan cheese, chopped parsley, egg, minced garlic, salt, black pepper, dried oregano, dried basil, and red pepper flakes (if using) to the breadcrumb mixture.
Mix all the ingredients together until well combined.
Shape the mixture into meatballs, about 1-2 inches (2.5-5cm) in diameter.
Place the meatballs on a plate or tray and refrigerate them for about 30 minutes to firm up.