Cook pasta as directed, adding zucchini the last 5 mins, drain. In small saucepan, combine broth and garlic. Bring to boil over high heat.
Cover, reduce to a simmer, simmer 15 mins. Transfer broth mix to blender, blend until smooth. Return mix to saucepan. Simmer over med-high heat. Add cornstarch mix. Whisk until thickened. Remove from heat. Whisk in sour cream, nutmeg and pepper. return to pot over low heat.
Put pasta mix in lg bowl. Add garlic sauce and 1/2 cup parmesan cheese, toss to coat. Sprinkle w/ parsley and remaining parmesan cheese.