Heat oil in a large saucepan over medium heat. Add onion, garlic and potato. Cook 5 minutes, stirring frequently. Add small amonts of water as necessary, about a tablespoon at a time, to prevent sticking.
2
Add broth, zucchini, and rosemary. When mixture boils, reduce heat to medium-low, cover and simmer 15 to 20 minutes, until zucchini is tender.
3
Puree soup in a blender in 2 or 3 batches, then return soup to saucepan. Add salt and pepper to taste.
