Heat the olive oil in a large pot over medium heat.
Add the sliced chicken sausages and cook until browned, about 5-7 minutes. Remove and set aside.
In the same pot, add the diced onion, salt, and minced garlic. Cook until the onion is softened, about 3-4 minutes.
If using, add the crushed red pepper and cook for an additional 1 minute.
Pour in the chicken broth and bring to a boil.
Stir in the pasta and cook according to package instructions, about 8-10 minutes, until al dente.
Add the chopped zucchini and cook for an additional 3-4 minutes, until tender.
Stir in the lemon juice, half of the Parmesan cheese, grape tomatoes, and the cooked chicken sausages.
Cook for an additional 2 minutes, until everything is heated through.
Remove from heat and stir in the chopped basil.
Garnish with the remaining Parmesan cheese before serving
