Heat 2 tbsp. oil in a large wide pot over medium-low heat. Add onion and cook, covered, until starting to soften, 5 minutes. Add pasta and more oil if it looks dry, then toast over medium-high heat, turning constantly with tongs, until golden. Add garlic and saffron (if using), tomatoes and tomato paste, sausages, and broth.
Boil pasta in soup, uncovered, until noodles are tender, about 5 minutes.
Add shrimp and cook just until pink and curled, about 1 minute. Season with salt to taste and stir in parsley.
Note: Nutritional analysis is per serving.