Heat the oil in a heavy large pot over medium heat. Add the leeks
and saute until translucent, about 8 minutes. Add the garlic and saute until tender, about 2 minutes. Stir in the zucchini
. Season the vegetables with salt and pepper. Saute until the zucchini are tender, about 10 minutes. Add the vegetable broth. Stir in the thyme and cook for 2 minutes. Cover the pot and bring the soup to a simmer
. Decrease the heat to medium-low and simmer gently until the flavors develop, stirring occasionally, about 20 minutes. Increase the heat to medium-high. Add the noodles and cook until al dente
, stirring constantly, about 5 minutes.
Ladle the soup
into bowls. Sprinkle with Parmesan and serve.