Toss farfalle pasta with vegetable oil in a large bowl.
Cook broccoli with 1 tbs salt in boiling water to cover 2 minutes or until crisp-tender; drain.
Plunge into ice water to stop the cooking process and drain.
Add broccoli and spinach to macaroni in bowl.
Melt butter in a saucepan over medium heat; add onion, and saute until tender.
Add mushrooms; cook 5 minutes.
Sprinkle with flour, stirring until blended.
Gradually stir in milk; cook over medium heat, stirring constantly, 15 minutes.
Add 1 1/2 cups cheese, remaining 1/2 tbs salt, whipping cream, pepper, and nutmeg, stirring until cheese melts.
Stir into macaroni mixture; spoon into a lightly greased 13- x 9-inch baking dish.
Sprinkle with remaining 1/2 cup cheese.
Bake at 375 degrees for 40 minutes or until set.
Ready in 1 hour.