Heat the oil in a pot over medium heat. Stir in orzo, and cook 2 minutes, until golden. Stir in garlic, zucchini, and carrot, and cook 2 minutes. Pour in the broth and mix in lemon zest. Bring to a boil. Reduce heat to low and simmer 10 minutes, or until liquid has been absorbed and orzo is tender. Season with thyme and top with Parmesan to serve.
