Bring large pot of salted water to boil. Cook pasta shells for 3/4 of the time on the package directions. Drain and set aside.
While pasta is cooking, chop veggies and preheat oven to 350 degrees.
Cooking the filling: In a large skillet, melt butter over medium-high heat. Sauté onion, garlic and asparagus for about 2 minutes before adding remaining vegetables and seasonings. Cook another 5-7 minutes or until tender. Pour into a bowl. Stir together with cottage cheese, Parmigiano Reggiano, eggs, salt and pepper.
Fill each shell with one heaping tablespoon of filling and place into a buttered casserole dish. Set aside.
Make the alfredo: Melt 1 cup butter over medium heat. Once butter is hot and crackling, whisk in heavy cream, Parmigiano Reggiano, salt and pepper. Whisk over medium heat until cheese melts, sauce comes together and is smooth. Pour over prepared shells and top with any remaining Parmesan cheese (optional).
Bake 30-40 minutes or until hot, bubbly and browned around the edges. Serve hot.
*I make the entire 12 oz. box of shells just incase there are a few broken ones. You could count out 30 shells if you don't want to cook them all!**I blend my cottage cheese in a blender to make it creamy and smooth because I like that texture better than cottage cheese on its own. Feel free to use as is or substitute ricotta cheese.