Roughly Chop Zucchini And Onion And Process Mushrooms, Zucchini And Onion In A Food Processor Until Finely Chopped. Melt Butter In A Large Skillet Over Medium Heat. Stir In Garlic And Chopped Vegetables. Reduce Heat, Cover And Simmer 20 Minutes, Until Tender And Juicy. Meanwhile, Bring A Large Pot Of Lightly Salted Water To A Boil. Add Pasta And Cook For 8 To 10 Minutes Or Until Al Dente; Drain. Stir Flour Into Vegetables. Stir In Cream Or Milk And Season To Taste. Let Simmer 10 Minutes More, Then Toss With Cooked Pasta.