In a medium saucepan combine the diced tomatoes, pasta sauce, diced onion, Italian herb mix, salt and water. Stir in the garlic then allow the mixture to simmer for 2 hours. If sauce seems dry add additional water.
In large saucepan of boiling salted water cook the ravioli until done. Drain.
In a 23x33cm baking dish layer sauce and cooked ravioli. Top with grated Parmesan cheese and grated mozzarella cheese.
In an oven preheated to 200 degrees C bake for 30 minutes or until light golden brown.