Put a large pot of water over high heat to boil.
TO MAKE THE PESTO: In a food processor, combine the pine nuts, basil,
2⁄3 cup parsley, oil, cheese, garlic, salt, and pepper. Process until medium smooth.
TO MAKE THE PASTA: Once the water is boiling, salt it and add the pasta. Cook for 5 minutes, then add the asparagus.
Meanwhile, in a medium skillet, heat the oil over medium heat. Add the mushrooms and cook for 7 minutes, or until tender.
When the pasta is cooked al dente, strain it and the asparagus, reserving ½ cup of the cooking water. Return the pasta and asparagus to the pot along with ¼ cup of the reserved cooking water. Mix in the pesto. Stir in the remaining ¼ cup cooking water. Top the pasta with the mushrooms and sprinkle with the chopped parsley.