Creamy Basil Zucchini Soup

Why I Love This Recipe
This is a Sunset Magazine reader's recipe which I've modified. It's wonderfully satisfying and fresh.
Ingredients You'll Need
1 Tbsp. olive oil
1 large onion, chopped
2 lbs. zucchini, sliced 1/4 inch thick
4 cups chicken broth
1 cup loosely packed basil leaves, washed and stemmed
2 Tbsp. whole greek yogurt, sour cream or creme fraiche + more for garnish
1/4 - 1/2 tsp. chili powder + more for garnish
Salt
Directions
1. Heat olive oil in a large saucepan over medium heat.
2. Add onion and cook until translucent, about 5 minutes.
3. Add zucchini and cook another 2 minutes.
4. Add chicken broth and basil.
5. Reduce heat to a simmer and cook 20 minutes.
6. Puree the soup with an immersion blender or in a blender, in batches.
7. Add 2 Tbsp. yogurt/or other and chili powder.
8. Season with salt to taste.
9. Divide soup among bowls and garnish each with some yogurt/or other, and a sprinkle of chili powder.
per 1 1/2-cup serving: 101 cal., 45% (45 cal.) from fat; 5.5 g protein; 5 g fat (1.7 g sat.); 11 g carbo. (2.5 g fiber); 440 mg sodium; 4.7 mg chol.