Pasta -- Cook the pasta according to directions. When it is done, just drain reserving 1 cup of the pasta water and return the pasta to the pot. NOTE: Whole wheat pasta does make a difference in this dish.
Sauce -- In a large sauce pan, add the butter and saute the onions for about 5 minutes until soft but not caramelized. Then add in the zucchini and cook another few minutes. They take just minutes to cook. Then add the walnuts, cream, parsley, rosemary, salt and pepper.
Combine -- Add the pasta to the sauce along with the parmesan and some of the pasta water and toss well. Garnish with some extra parmesan if you want. ENJOY!