In a large pot, bring to a boil 4 quarts of salted and oiled water. Carefully add small batches of ravioli, about 3 to 4 at a time. This will prevent them from crowding in the pot and sticking together. Cook for 2 to 3 minutes. Using a spider strainer, carefully remove the ravioli and place on the plate. Tent with foil to keep warm and continue cooking remaining ravioli.
In a saute pan, heat remaining 1/4 cup olive oil. When almost smoking, add chopped mushrooms and sauté until soft and most of the liquid has evaporated, about 8 minutes. Carefully pour in tomato sauce and simmer for 5 minutes.

Divide ravioli between 2 serving plates. Top with mushroom tomato sauce and sprinkle with Parmesan.

Simple Tomato Sauce:
1/2 cup extra-virgin olive oil
1 small onion, chopped
2 cloves garlic, chopped
1 stalk celery, chopped
1 carrot, chopped
Sea salt and freshly ground black pepper
2 (32-ounce) cans crushed tomatoes
2 dried bay leaves
4 tablespoons unsalted butter, optional

In a large casserole pot, heat oil over medium high heat. Add onion and garlic and saute until soft and translucent, about 5 to 10 minutes. Add celery and carrots and season with salt and pepper. Saute until all the vegetables are soft, about 5 to 10 minutes. Add tomatoes and bay leaves and simmer uncovered 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 1/2 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.