Cook and drain pasta in salted water according to manufacturer's directions; set aside.
Heat 1 ounce Clarified Butter in large sauté pan. Add asparagus; sauté until crisp-tender. Season with 1/2 teaspoon black pepper and 1/2 teaspoon salt. Remove from pan; set aside.
Heat remaining 1 ounce Clarified Butter in same pan. Add mushrooms and garlic; sauté until softened. Season with remaining 1/2 teaspoon black pepper and 1/2 teaspoon salt. Stir in stock. Add Alfredo Sauce and red pepper flakes; stir to combine. Add asparagus and cooked pasta. Cook and stir until pasta is coated with sauce and mixture is heated through. Serve sprinkled with Parmesan.