This soup is best made a day ahead. Let it chill thoroughly in the refrigerator to let the flavors meld. Of course, you could use red summer tomatoes, but the all-yellow color palette here creates a particularly bright and sunny dish.
- 6 tablespoons extra-virgin olive oil
- 1 small sweet onion, finely chopped
- 1 stalk celery, finely chopped
- 1 yellow bell pepper, finely chopped
- 2 teaspoons chopped fresh rosemary
- 2 pounds ripe yellow tomatoes, chopped
- 4 ears corn, kernels removed from the cob (about 2 cups kernels)
- 6 cups water
- Kosher salt and peperoncino
- 1/2 cup full-fat Greek yogurt, plus more for serving
- White wine vinegar
- Diced tomato, corn kernels, celery leaves, chopped chives, and extra-virgin olive oil for garnish
Heat 3 tablespoons of the olive oil in a medium Dutch oven over medium heat. Add the onion, celery, bell pepper, and rosemary. Cook, stirring occasionally, until softened, about 5 minutes. Add the tomatoes and cook until they begin to break down, about 4 minutes. Add the corn, 6 cups water, 2 teaspoons salt, and a large pinch of peperoncino. Bring to a simmer and cook until all of the vegetables are tender, about 15 minutes. Remove from the heat and let cool slightly.
Add the yogurt and vinegar to the pot and blend with an immersion blender (or use a regular blender, blending in batches). Drizzle in the remaining olive oil and blend until smooth and glossy. Cover and chill until very cold, at least 3 hours, preferably overnight.
Serve in chilled bowls or glasses, garnished with yogurt, diced yellow tomato, corn kernels, celery leaves, chopped chives, and a drizzle of olive oil.