* Preheat oven to 400°F (200°C).
* On a baking sheet, toss tomatoes, onion, and garlic with olive oil, salt, pepper, thyme, basil, oregano, and smoked paprika.
* Roast for 25–30 minutes, or until tomatoes are blistered and garlic is golden.
* While the veggies roast, cook the fettuccine in salted boiling water until al dente.
* Reserve ¼ cup pasta water, then drain and set aside.
* Transfer roasted tomatoes, onion, and garlic (with juices) to a blender or food processor.
* Add chicken broth and blend until smooth and creamy. (For a chunkier sauce, pulse a few times instead.)
* Pour the sauce into a large skillet over medium heat.
* Stir in heavy cream and let simmer for 2–3 minutes.
* Add Parmesan cheese and stir until melted and the sauce is velvety.
* Toss in cooked fettuccine and stir to coat evenly. Add a splash of pasta water if needed to loosen the sauce.
* Plate the pasta and garnish with red chili flakes, fresh parsley, and extra Parmesan if desired.