Preheat oven to 375 degrees F (190 degrees C). Trim asparagus. Cut stalks into 1-inch (2.5 cm) pieces. In large pot of boiling water, cook asparagus for 3 minutes.

Drain and refresh under cold water. Drain again. Remove 1 1/2 cups (375 mL) asparagus tips. Set aside. In saucepan, melt butter over medium heat. Whisk in flour and cook, whisking, for 1 minute. Gradually whisk in milk.

Bring to boil. Reduce heat to medium-low. Cook, stirring, for 10 minutes or until thickened. Remove from heat. Stir in goat cheese, lemon rind and juice, salt, pepper and nutmeg until cheese has melted.

Meanwhile, in large pot of boiling salted water, cook noodles for 6 to 8 minutes or until almost tender. Drain and cool in cold water. Remove and arrange in single layer on damp tea towel. Arrange 3 noodles in single layer in greased 13- x 9-inch (3 L) glass baking dish. Spread with 1 cup (250 mL) of the sauce, then one-quarter of the mozzarella.

Repeat layers 3 more times. Top with final layer of noodles and sauce. Sprinkle Parmesan over top. Bake in oven for 35 to 40 minutes or until light golden and bubbly. Sprinkle reserved asparagus tips over top. Bake for 5 minutes or until asparagus is heated through. Let stand for 10 minutes before serving.