Cook pasta in boiling water 6 minutes, omitting salt and fat. Add asparagus, and cook 2 minutes or until tender.
While pasta is cooking, melt butter in a medium saucepan over medium-high heat. Add garlic, and cook for 3 minutes. Add flour; cook 30 seconds, stirring constantly. Gradually add milk, stirring well with a whisk. Stir in cream cheese and salt; cook 3 minutes or until thick, stirring constantly.
Drain pasta and asparagus; place in a large bowl. Add sauce; tossing to coat. Serve with Gorgonzola and walnuts, and sprinkle with pepper, if desired.