In a large saucepan, crumble and cook sausage and onions over medium heat until sausage is browned. Drain if necessary. Add remaining ingredients and bring to a boil. Reduce heat to low and simmer 20 minutes or until pasta is cooked and zucchini is tender.
I use this recipe as a base and then usually double or triple. If you want a thinner "soup" then use only 1/2 cup pasta. If you like more of a stew use at least 1 cup of pasta and two small zucchini.