Preheat the oven to 500 degrees F.
Stir the oil and herbs in a small bowl to blend. Season with salt and pepper. Brush both sides of the cutlets with the herb oil. Heat a heavy large oven-proof skillet over high heat. Add the cutlets and cook just until brown, about 2 minutes per side. Remove the skillet from the heat.
Spoon the marinara sauce over and around the cutlets. Sprinkle 1 teaspoon of mozzarella over each cutlet, then sprinkle 2 teaspoons of Parmesan over each. Sprinkle the butter pieces atop the cutlets. Bake until the cheese melts and the chicken is cooked through, about 3 to 5 minutes.
In a large casserole pot, heat oil over medium high heat. Add onion and garlic and saute until soft and translucent, about 2 minutes. Add celery and carrots and season with salt and pepper. Saute until all the vegetables are soft, about 5 minutes. Add tomatoes, basil, and bay leaves and simmer covered on low heat for 1 hour or until thick. Remove bay leaves and check for seasoning. If sauce still tastes acidic, add unsalted butter, 1 tablespoon at a time to round out the flavors.
Add half the tomato sauce into the bowl of a food processor. Process until smooth. Continue with remaining tomato sauce.
If not using all the sauce, allow it to cool completely and pour 1 to 2 cup portions into freezer plastic bags. This will freeze up to 6 months.