In your soup pot melt butter, add carrot, celery, leek & garlic. Saute until leek is soft. Add broth & bring to a boil, lower heat & simmer for 10 minutes. Increase heat & add tortellini, basil & parsley. Let pasta cook for about 2 minutes & add zucchini. Cook until pasta is tender, add shrimp & heat briefly. Do not recook the shrimp.