Mince the onion and separate Italian parsley leaves from stems, tearing the leaves into small pieces.

Place minced onion in a microwave-safe container, cover loosely with plastic wrap, and microwave at 600W for 1 minute. Let cool.

In a bowl, soak breadcrumbs in milk. Add remaining meat mixture ingredients and knead until sticky. Shape into bite-sized meatballs.

Heat salad oil in a frying pan, add meatballs, and cook until browned on all sides. Cover and cook for 15 minutes, then remove.

In the same pan, melt butter, add flour, and mix. Add remaining sauce ingredients and stir over low heat until smooth.