Preheat the oil to 300 degrees F in a deep pot or deep-fryer.
Remove the stems from the mushrooms and then stuff each mushroom with 1 to 1 1/2 ounces of sausage.
Create a standard breading station in 3 separate 8-by-8-inch pans: Combine the flour, 1 tablespoon salt and 2 teaspoons pepper into the first pan. Whisk together the eggs and the milk in the second pan. Place the breadcrumbs in the third pan.
Dredge each of the stuffed mushrooms in the flour, coat with the egg wash and then with the breadcrumbs.
Fry the mushrooms, in batches if necessary, until golden brown and the sausage is fully cooked, 8 to 10 minutes.
Heat the Tomato Sauce in a saucepan. Spoon 1/4 cup sauce onto the center of each plate. Arrange 3 fried mushrooms on top of the sauce. Garnish each plate with chopped parsley and Parmesan.
Combine the whole tomatoes and their liquid, the olive oil, onion, basil, oregano, salt, pepper and 4 cloves garlic in a large bowl or 2-gallon container and puree with an immersion blender until smooth.
Heat a large saute pan over high heat until it begins to smoke. Reduce the heat to medium, add the grapeseed oil and remaining 4 cloves garlic and quickly saute. Add the diced tomatoes and saute for 1 to 2 minutes. Add the pureed tomato sauce and bring to a simmer. Cook for 15 minutes, remove from the heat. Bring back to a simmer when you are ready to plate. Yield: 6 servings