heat olive oil in a skillet over medium heat for about 30 seconds. add garlic for about another 20 seconds.
add onions to skillet and saute for about 2 minutes. add sausage and brown for about 3 minutes. drain.
transfer sausage/onion to a big pot. add the rest of the ingredients to the pot and heat to boiling.
reduce heat to low. cover and simmer about 10-15 minutes until zucchini is tender and flavors have melded together. (the longer the better, this soup is actually better the next day!)
add salt and pepper to taste. top with parsley, sprinkle with Parmesan cheese and Enjoy!