- Toss zucchini with garlic, onion, olive oil, salt and pepper and spread on a sheet pan. Roast 425F about 25 minutes, until tender and browned, tossing halfway. 
- Meanwhile, bring a large pot of salted water to a boil. When boiling, add the pasta and cook according to package directions for al dente. 
- Drain the pasta reserving some of the water and return to the pot. 
- Remove the vegetables from the oven when done and transfer to a blender. Add the parmesan cheese and broth. Puree until smooth. 
- Toss with the pasta, adding reserved water, as needed to loosen the sauce to your desired taste. 
- Top with fresh black pepper and serve with Parmesan cheese, if desired.