Combine milk and egg in a small bowl. Place breadcrumbs and salt in a shallow bowl. Dip ravioli in milk mixture and coat with breadcrumbs.
In a large saucepan, heat pasta sauce over medium heat until bubbling. Reduce the heat to simmer.
In a large heavy pan, pour oil to depth of 5cm. Heat oil over medium heat until a small amount of breadcrumb coating sizzles and turns brown. Fry ravioli, a few at a time, 1 minute on each side or until golden. Drain on paper towels. Sprinkle with Parmesan cheese and serve immediately with hot pasta sauce.