Step 1

Heat the oil (or several tablespoons water, for oil-free) in a heavy large saucepan over medium-high heat. Add onions; cook and stir 5 to 6 minutes until softened.

Step 2

Add the potato and zucchini; cook and stir for 2 minutes.

Step 3

Add the water, herbs,  and 3/4 teaspoon salt and bring to boil. Reduce heat to medium-low, cover, and simmer for 15 to 20 minutes or until vegetables are tender, about 15 to 20 minutes.

Step 4

Purée soup in batches in a high-speed blender. Return puree to same pan. Cook and stir over low heat to warm through. Season with salt and pepper to taste. Garnish with zucchini strips, if desired.