Heat olive oil in large skillet or dutch oven over medium-high heat. Add onions and garlic and saute for a minute or two. Add Italian sausage and brown, breaking it up into small pieces as it cooks. Pour in red wine and let it cook for a minute or two.
Pour in cans of crushed tomatoes and stir. Add sugar and salt. Bring to a boil, then reduce heat to low. Cover and cook 30 to 45 minutes, stirring occasionally. Check for seasonings; can add crushed red peppers if you like a little heat.
In a separate bowl, mix ricotta, half the Parmesan, Romano, egg, salt and pepper, basil, and 2 tablespoons parsley. Stir until combined.
To assemble, coat the bottom of a baking dish with sauce. Fill each half-cooked shell with the cheese mixture. Place face down on the sauce. Repeat with shells until cheese mixture is gone. Top shells with remaining sauce. Sprinkle on extra Parmesan.
Bake at 350 degrees for 25 minutes, or until hot and bubbly.
Serve with crusty French bread.