This soup is great as is, or adding the optional dairy/non-dairy to give it added richness.  It’s particularly refreshing served chilled.

1 large onion, chopped
olive oil
2# zucchini, cut into chunks
2 T curry powder
4 C vegetable or chicken stock
salt & pepper to taste
OPTIONAL: yogurt or similar (buttermilk, sour cream) or milk substitute, such as coconut or almond milk, one to two cups

In a large pot or pan, heat about 2-3 T olive oil; add onions and cook until translucent, about three minutes.  Add zucchini.  Add curry powder (more or less, according to your taste).  Stir, cover and reduce heat to simmer. Cook until vegetables are tender, about 10 minutes.
Add chicken stock to cover – you may not need all four cups. Pure the soup, using an immersion blender or a food processor.  Taste for seasoning.  Add dairy/non-dairy if using.  Serve hot or chill at least four hours.