Preheat oven to 425F. In a large skillet heat 1 tablespoon oil and saute the onions, carrots, celery and garlic over medium heat for five minutes. Add the herbs and sliced sausage; saute two minutes. Add all ingredients to a three-quart casserole dish; stir, cover and bake in the oven for 30 minutes. Remove from oven and add salt and pepper to taste. Garnish with shredded Parmesan cheese if desired.