Bring a large pot of lightly salted water to a boil over high heat. Add the egg pasta and cook until al dente, 8 to 10 minutes. Drain in a colander, rinse with cold water and set aside.
Meanwhile, place the zucchini and water into a 2L microwave safe casserole dish with lid. Cover and cook in the microwave on high for 6 minutes. Scrape the zucchini into the colander with the pasta and set aside. Place the butter, mushrooms, onion and garlic into the casserole dish. Cook on high for 3 minutes, then stir in the flour, salt and basil. Stir in the milk, then return the dish to the microwave and cook on high 5 minutes more, stirring every 2 minutes.
Stir the zucchini and pasta into the mushroom sauce along with 1 cup (115g) of the Gouda cheese. Cook for 6 more minutes on high, then sprinkle with the remaining cheese and cook another minute until the cheese has melted.