Bechamel Sauce: Melt butter in a 2-quart saucepan over medium heat. Stir in flour and cook for 1 minute. Add milk and bouillon and stir vigorously with a wire whip until mixture barely comes to a boil. Reduce heat and simmer for 5 minutes, whipping frequently. Keep warm.
Drain broccoli and divide in half. Chop 1/2 of florets into 1/4-inch pieces. Reserve.
Heat a large sauté pan over medium heat and add olive oil. Add all the broccoli, garlic, green onions and mushrooms to the sauté pan. Cook, stirring constantly, for 2 minutes or until mushrooms begin to turn golden. Add the sautéed veggies and parsley to the warm sauce and stir well.
Serve over hot pasta with Parmesan.
Makes: 4