Heat a large pan of lightly salted water to boiling over high heat. Peel the asparagus stalks and trim the ends. Cut the stalks into 2-inch pieces. Blanch in boiling water 3 minutes or until bright green and crisp-tender when tested with a small knife. With a slotted spoon, remove the asparagus and rinse under cold water to stop the cooking. Add the spaghetti to the boiling water and cook according to the label directions until al dente. Drain.
Meanwhile, in a medium saucepan over medium-high heat, melt the butter. Blend in the flour with a whisk. add the broth and cook for 2 minutes, stirring constantly, until the sauce thickens. Blend in the goat cheese and the lemon peel.
Toss the spaghetti with the asparagus, sauce and half the Parmesan. Serve with the remaining Parmesan and freshly ground black pepper.