Preheat the oven to 350 degrees . In a large pot, heat 2 tbsp. EVOO over medium heat. Add the onion and garlic; cook for 5 minutes. Add 2 cans of tomatoes. Strain the remaining 4 cans; add the tomatoes to the pot. Using a wooden spoon, break up some of the tomatoes; simmer for 20 minutes. Turn off the heat, discard the garlic and add the basil; season.
In a shallow bowl, whisk the eggs and milk. In a large, shallow dish, mix the breadcrumbs with 1/2 cup each parmesan and mozzarella. Coat the chicken in the egg mixture; transfer to the breadcrumbs, turning to coat.
In a large skillet, heat 2 tbsp. EVOO over medium heat. Cook the chicken in batches until golden on both sides, about 5 minutes total. (Wipe out the skillet and add more EVOO as needed.) Drain on paper towels.
In a 10-by-13 1/2-inch (8 qt.) baking dish, layer the sauce, chicken and remaining 3 1/2 cups mozzarella, finishing with a layer of sauce. Top with the remaining 1 cup parmesan. Bake until the cheese is melted, 20 minutes. Serve with rigatoni, salad and italian bread.