1. Using a vegetable peeler, make parmesan shavings.
2. In a large quantity of boiling salted water, cook the spaghetti al dente. Drain and set aside.
3. In a large saucepan, heat the olive oil.
4. Add the onion and cook until it is transparent. Add the zucchinis in chunks and cook over medium heat for 4 minutes, stirring. Add the vegetable broth and saffron.
5. Remove the pistil from the zucchini flowers. Slice the zucchini flowers into strips. Add the sliced zucchini flowers to the saucepan. Cover and heat over low heat for a few minutes.
6. Add the spaghetti to the vegetables and mix well.
7. To serve, transfer portions of spaghetti and vegetables onto plates and sprinkle with parmesan shavings.