In a large pot, bring 6 quarts of salted water to a boil. Cook pasta to al dente, drain and return to pot. Set aside.
While water is heating, add 1-2 Tbsp olive oil in a large sauté pan over high heat, add Italian sausage and cook until golden brown, breaking up lumps.
Pour sausage into a large bowl. Set aside.
Add 1-2 Tbsp olive oil into pan, add mushrooms. Sauté until the liquid from the mushrooms have evaporated, about 5 minutes.
Pour mushrooms into the bowl with the sausage.
Add another 1-2 Tbsp olive oil into sauté pan, add chopped asparagus. Cook until bright green, but not soggy. Pour asparagus into the same bowl with the sausage and mushrooms.
To the pasta, add 1/2 C olive oil, salt and pepper and the bowl of sausage, mushrooms and asparagus. Top it off with parmesan.
Serve straight from the pot along with crusty bread and extra olive oil on the side.