Step 1

In a large frying pan, melt butter or margarine; add onion and saute until translucent. Add diced potato, zucchini, thyme, rosemary, basil, and white pepper, and cook for 5 minutes.

Step 2

In a medium-sized cooking pot, add broth and bring to boil. Add zucchini/potato mixture; reduce heat and simmer about 15 minutes.

Step 3

When cooked, puree in food processor or blender in batches. Return to cooking pot, add milk and bring just to boil, but do not boil. Add instant mashed potato flakes and soy sauce and stir well. Adjust seasonings to taste. Garnish with dill weed. Soup may be served hot or chilled.