Heat a saucepan or skillet over medium heat then add in the olive oil. When hot, add in the sausage and onion all at once and stir occasionally until sausage is lightly browned.
Add in the salt, pepper and then the garlic for 1 minute. Pour the broth in and with a non-scratching spatula, scrape any bits from the pan into the broth. Let it come to a boil and toss in the uncooked pasta. Lower heat to a med-low and let it cook for 8 - 10 minutes, stirring often. Once pasta is mostly cooked stir in the zucchini and cook additional 3-4 minutes.
Add in the lemon juice, about 3/4 of the parmesan cheese and the tomatoes.
Serve with a garnish of fresh basil and a sprinkle of parmesan cheese on top!